ME’scopeVES Tutorial Manual Volume IA – Basic Operations
(February 2014)
Notice Information in this document is subject to change without notice and does not represent a commitment on the part of Vibrant Technology. Except as otherwise noted, names, companies, and data used in examples, sample outputs, or screen shots, are fictitious and are used solely to illustrate potential applications of the software.
Warranty Vibrant Technology, Inc. warrants that (a) the software in this product will perform substantially in accordance with the accompanying documentation, for a period of one (1) year from the date of delivery, and that (b) any hardware accompanying the software will be free from defects in materials and workmanship for a period of one (1) year from the date of delivery. During this period, if a defect is reported to Vibrant Technology, replacement software or hardware will be provided to the customer at no cost, excluding delivery charges. Any replacement software will be warranted for the remainder of the original warranty period or thirty (30) days, whichever is longer. This warranty shall not apply to defects resulting from improper or inadequate maintenance by the customer, customer supplied software or interfacing, unauthorized modification or misuse, operation outside of the environmental specifications for the product, or improper site preparation or maintenance. In the event that the software does not materially operate as warranted above, the sole remedy of the customer (and the entire liability of Vibrant Technology) shall be the correction or detour of programming errors attributable to Vibrant Technology. The software should not be relied on as the sole basis to solve a problem whose incorrect solution could result in injury to a person or property. If the software is employed in such a manner, it is at the entire risk of the customer, and Vibrant Technology disclaims all liability for such misuse. NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. VIBRANT TECHNOLOGY SPECIFICALLY MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER'S SOLE AND EXCLUSIVE REMEDIES. VIBRANT TECHNOLOGY SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, PERFORMANCE, OR USE OF THIS PRODUCT, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
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Table of Contents Overview ......................................................................................................................... 1 Introduction ..................................................................................................................... 1 Observing Vibration in Slow Motion ............................................................................. 2 ME'scopeVES Packages & Options ................................................................................ 2 Signal Processing Option ............................................................................................ 3 Acoustics Option .......................................................................................................... 3 Basic Modal Analysis Option ....................................................................................... 3 Multi-Reference Modal Analysis Option ....................................................................... 4 Operational Modal Analysis (OMA) Option .................................................................. 4 Multi-Input Multi-Output (MIMO) Modeling & Simulation Option .................................. 4 Structural Dynamics Modifications (SDM) Option ........................................................ 4 Experimental Finite Element Analysis (FEA) Option .................................................... 4 FEA Model Updating Option ........................................................................................ 4 Direct Data Acquisition Options ................................................................................... 5 Program Option ........................................................................................................... 5 Types of Measurements Imported ................................................................................... 5 Time Domain Functions ............................................................................................... 5 Frequency Domain Functions ...................................................................................... 5 Order Tracked Responses ........................................................................................... 6 Time-Based ODS Animation ........................................................................................... 6 Frequency-Based ODS Animation .................................................................................. 6 Mode Shape Animation ................................................................................................... 7 Documentation with Digital Movies™ .............................................................................. 8 How the Operating Manual is Organized......................................................................... 9 Installation ................................................................................................................... 9 Tutorials ....................................................................................................................... 9 Volume IA - Basic Operations .................................................................................. 9 Volume IB - Options ............................................................................................... 10 Command References ............................................................................................... 10 Volume IIA - Basic Operations ............................................................................... 10 Volume IIB - Options .............................................................................................. 10
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Tutorial Volume IA - Basic Operations Help Windows ............................................................................................................ 10 Table of Contents ................................................................................................... 11 Index ...................................................................................................................... 11 Search.................................................................................................................... 11 Glossary ................................................................................................................. 11 Installation ..................................................................................................................... 13 Computer System Requirements .................................................................................. 13 Installing the Software ................................................................................................... 13 Installing from the Installation CD ROM ..................................................................... 13 Installing Software Downloaded from the Internet ..................................................... 13 Running the Installer Program MEscopeVES_Setup.EXE......................................... 13 The Security System ..................................................................................................... 16 If ME'scope Won't Run .............................................................................................. 16 Help | About Box ........................................................................................................ 17 Registering for User Support ......................................................................................... 17 Introduction to ME'scope ............................................................................................... 19 Projects, Data Files, and Windows ................................................................................ 19 ME'scope Window ..................................................................................................... 19 Data File Windows ..................................................................................................... 19 Saving Data Files....................................................................................................... 20 Mouse Operations ......................................................................................................... 20 Window Operations ....................................................................................................... 21 Center a Window in the Work Area ........................................................................ 21 Center the ME'scope Window on the Desktop ....................................................... 21 Make a Window Active ........................................................................................... 21 Move a Window...................................................................................................... 21 Re-size a Window .................................................................................................. 21 Close a Window ..................................................................................................... 21 Maximize a Window ............................................................................................... 21 Minimize (Icon) a Window ...................................................................................... 21 Restore a Minimized Window ................................................................................. 21 Tool Tips ....................................................................................................................... 21 Help | Show Tool Tips ................................................................................................ 22 iv
Table of Contents Command Toolbars ....................................................................................................... 22 Moving a Toolbar ................................................................................................... 22 Customizing Toolbars ............................................................................................ 22 Adding a Tool to a Toolbar ..................................................................................... 23 Move a Tool to Another Toolbar ............................................................................. 23 Reposition a Tool on a Toolbar .............................................................................. 23 Remove a Tool from a Toolbar............................................................................... 23 Create a New Toolbar ............................................................................................ 23 Locking the Toolbars .............................................................................................. 24 Hidden Floating Toolbars ....................................................................................... 24 Resetting the Toolbars ........................................................................................... 24 The ME'scope Window .................................................................................................. 24 Project Fly-Out Panel................................................................................................. 24 Work Area .................................................................................................................. 25 Project Folder Tabs ....................................................................................................... 25 Opening a Project From a Folder Tab ....................................................................... 25 Moving a Fly-out Panel .............................................................................................. 25 Creating a New Folder Tab........................................................................................ 26 Opening a Project ......................................................................................................... 26 Opening a Previously Saved Project file .................................................................... 27 Creating a New Project .............................................................................................. 27 Creating a New Data File ........................................................................................... 27 Adding a File from Another Project ............................................................................ 27 Importing a Data File ................................................................................................. 27 Structure (STR) Window ............................................................................................... 27 Adding a Structure Model to a Project ....................................................................... 28 Data Block (BLK) Window ............................................................................................. 28 Adding a Data Block to a Project ............................................................................... 29 Shape Table (SHP) Window ......................................................................................... 29 Adding a Shape Table to a Project ............................................................................ 30 Time-Based ODS Demo................................................................................................ 31 Changing the Animation Speed ................................................................................. 32 Quad View versus Single View .................................................................................. 32 v
Tutorial Volume IA - Basic Operations Active View ................................................................................................................ 32 Zoom ......................................................................................................................... 33 Pan ............................................................................................................................ 33 Rotation in the 3D View ............................................................................................. 33 Interpolated Motion .................................................................................................... 33 Frequency-Based ODS Demo ....................................................................................... 33 Animating Near a Resonance .................................................................................... 33 Trace Display Formats............................................................................................... 34 Mode Shape Demo ....................................................................................................... 35 Contour Colors .......................................................................................................... 35 Acoustic Intensity Demo ................................................................................................ 36 Digital Movie Demo ....................................................................................................... 37 Tutorial #1 - Frequency-Based ODS Animation ............................................................ 39 Plate Model ................................................................................................................... 39 Step 1. Drawing the Plate Model ................................................................................... 40 Coordinate Units ........................................................................................................ 40 Using the Drawing Assistant ...................................................................................... 40 Step 2. Importing Measurements .................................................................................. 41 DOFs for a Roving Impact Test ..................................................................................... 43 Trace DOFs ............................................................................................................... 43 Trace Units ................................................................................................................ 44 Animation Equations ..................................................................................................... 44 Current Animation Source ......................................................................................... 44 Assigning M#s to Measurement Points & Directions ..................................................... 45 Point Numbering ........................................................................................................ 45 Point Label................................................................................................................. 46 Measurement Axes .................................................................................................... 46 Step 3. Creating Measured Animation Equations.......................................................... 47 Examining the Animation Equations .......................................................................... 48 Step 4. Frequency-Based ODS Animation .................................................................... 48 Zoom & Pan the Trace Display .................................................................................. 49 Structure Window Commands ................................................................................... 49 Changing Surface Colors........................................................................................... 50 vi
Table of Contents Tutorial #2 - Drawing Structure Models ......................................................................... 51 Requirements for Animation .......................................................................................... 51 Types of Drawing Objects ............................................................................................. 51 Point Coordinate Units .................................................................................................. 52 Types of Models ............................................................................................................ 52 Wire frame or stick model ...................................................................................... 52 Surface model ........................................................................................................ 52 Texture or photo realistic model ............................................................................. 52 Example 1. Creating a Cone SubStructure ................................................................... 52 Example 2. Building the Jim Beam with Plate SubStructures........................................ 54 Bottom Plate .............................................................................................................. 55 On the SubStructure tab ........................................................................................ 55 On the Dimensions tab........................................................................................... 55 On the Position tab................................................................................................. 55 Top Plate ................................................................................................................... 56 Back Plate ................................................................................................................. 57 On the SubStructure tab ........................................................................................ 57 On the Dimensions tab........................................................................................... 57 In the SubStructure spreadsheet............................................................................ 57 Quad View and Active View .......................................................................................... 58 Active View ................................................................................................................ 58 Zoom & Pan .................................................................................................................. 58 Example 3. Creating a Plate with Points, Lines & Surfaces .......................................... 58 Global Axis Lines ....................................................................................................... 59 Larger Point Size ....................................................................................................... 59 Re-Arranging Spreadsheet Columns ......................................................................... 59 Adding Points ................................................................................................................ 60 Editing Point Coordinates .............................................................................................. 61 Adding Lines to the Model ............................................................................................. 63 Adding Surfaces to the Model ....................................................................................... 64 Creating a SubStructure ................................................................................................ 65 SubStructure Library .................................................................................................. 65 Example 4. Extruding a 2D SubStructure ...................................................................... 65 vii
Tutorial Volume IA - Basic Operations Extruding the Cross Section ...................................................................................... 69 Example 5. Tracing Profile from a Photograph .............................................................. 70 Tracing a Car Profile .................................................................................................. 71 Adding Wheels .......................................................................................................... 73 Tutorial #3 - Importing Measurement Data .................................................................... 75 Requirements for Animation .......................................................................................... 75 Measurement Types...................................................................................................... 75 Time Domain Measurements ........................................................................................ 75 Repeatable Acquisition .............................................................................................. 76 Frequency Domain Measurements ............................................................................... 76 Steady State Acquisition ............................................................................................ 76 Cross-Channel Measurements .................................................................................. 77 FRF Measurements ................................................................................................... 77 Operating Data .......................................................................................................... 77 Importing a Data Block .................................................................................................. 78 Selecting Multiple Files .............................................................................................. 78 Translate Files Dialog Box ......................................................................................... 78 Tutorial #4 - Time-Based ODS Animation ..................................................................... 81 Requirements for Animation .......................................................................................... 81 Animation Equations ..................................................................................................... 81 Measured, Interpolated, and Fixed DOFs .................................................................. 81 Creating Animation Equations ....................................................................................... 82 Current Animation Source ......................................................................................... 82 Creating Measured Animation Equations .................................................................. 83 Matching Structure and Source DOFs ....................................................................... 83 Displaying Measured DOFs .......................................................................................... 85 Creating Interpolated Equations .................................................................................... 85 Deformed and Un-deformed Structure....................................................................... 87 Animation From a Data Block........................................................................................ 88 Animation Methods .................................................................................................... 88 Sweep Animation ....................................................................................................... 88 Sine or Stationary Dwell ............................................................................................ 88 Animation Speed ........................................................................................................... 88 viii
Table of Contents Data Block Sweep Speed .......................................................................................... 88 Sine Dwell Speeds..................................................................................................... 89 Animation Amplitude ..................................................................................................... 89 Shape Scaling ............................................................................................................... 89 Auto Scaling .............................................................................................................. 89 Relative Scaling ......................................................................................................... 89 Fixed Scaling ............................................................................................................. 89 Deformation, Arrows, and Contours .............................................................................. 90 Deformed Animation .................................................................................................. 90 Animation with Arrows ............................................................................................... 90 Contour Colors .......................................................................................................... 90 Contour Node Lines ................................................................................................... 91 Terminating Shape Animation ....................................................................................... 91 Tutorial #5 - Documenting Results ................................................................................ 93 Making a Digital Movie .................................................................................................. 93 The Windows Clipboard ................................................................................................ 94 Copy Graphics to Clipboard....................................................................................... 95 Copying Spreadsheet Cells ....................................................................................... 95 Save Graphics in a File ................................................................................................. 95 Printing .......................................................................................................................... 95 Structure, Data Block, and Acquisition....................................................................... 95 Shape Table .............................................................................................................. 95 Glossary ........................................................................................................................ 97 Index ........................................................................................................................... 111
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Overview Introduction NOTE: To enlarge this text, click on it, hold down the Ctrl key and spin the mouse wheel. The ME’scopeVES (Visual Engineering Series) is a family of software packages and options that makes it easier for you to observe, analyze, and document noise & vibration problems in machinery and structures. Using ME'scope you can do the following; •
Vibration & Acoustic Data Acquisition
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Vibration & Acoustic Signal Processing
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Operating Deflection Shape (ODS) Analysis
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Experimental Modal Analysis (EMA)
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Operational Modal Analysis (OMA)
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Vibro-Acoustic Shape Animation & Analysis
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Multi-Input Multi-Output (MIMO) Modeling & Simulation
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Structural Dynamics Modification (SDM)
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Experimental Finite Element Analysis (FEA)
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FEA Model Updating
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Tutorial Volume IA - Basic Operations
Animation of a Photo Realistic Model. ME'scope contains a state-of-the-art interactive animated display of spatially defined shapes on a 3D model of a machine or structure. Shape data such as an operating deflection shape (ODS), mode shape, acoustic intensity shape, or sound power through a surface can be displayed in animation on a photo realistic model, like the one shown above. Displaying shapes in animation makes it easier to visualize and analyze structural noise & vibration problems. Observing Vibration in Slow Motion By animating the spatial response of a structure in slow motion, you can view overall motion of a structure, and the motion of one part relative to another. Locations of excessive vibration or high noise levels are easily identified. •
With interactive sweep animation, you can sweep through a set of time histories and observe the recorded response of a structure, whether it is sinusoidal, random, transient, linear or non-linear, stationary or non-stationary.
•
With interactive dwell animation, you can dwell at a specific time or frequency in a set of responses, and display shapes using either sine dwell or stationary dwell.
ME'scopeVES Packages & Options
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Overview ME'scopeVES (Visual Engineering Series) can be purchased in a variety of packages and options. The basic package (Visual ODS™) contains all of the features necessary for drawing or importing a structure model, importing multi-channel measurement data, and interactively displaying shapes in animation on the structure model. All of the other ME'scopeVES packages add one or more of the following advanced capability options to Visual ODS™. •
Signal Processing
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Acoustics
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Basic Modal Analysis
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Multi-Reference Modal Analysis
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Operational Modal Analysis (OMA)
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Multi-Input Multi-Output (MIMO) Modeling & Simulation
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Structural Dynamics Modifications (SDM)
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Experimental Finite Element Analysis (FEA)
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FEA Model Updating
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Direct Data Acquisition
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Program
Signal Processing Option This option contains a Fast Fourier Transform (FFT) & Inverse FFT that make it easy to analyze signals and animate ODS's from either time or frequency domain data. It includes Notch, Band, Exponential, and other types of windows so that selected ranges of data can be analyzed, and unwanted portions removed. It also includes waveform Cut, Copy & Paste, waveform integration & differentiation, and a wide variety of waveform math functions. This Option also calculates Fourier Spectra, Auto & Cross Spectra, Power Spectral Density (PSD) and ODS FRFs, using time domain windows, triggering, averaging and overlap processing. A set of Fourier Spectra, Cross Spectra, or ODS FRFs can be used for ODS animation and Operating Modal Analysis (OMA). Additionally, a set of ODS FRFs provides a true measure of the amplitude & phase of each Degree Of Freedom (DOF) of a machine or structure. Acoustics Option This option allows you to post-process and display acoustic data obtained from Acoustic Intensity, Sound Pressure Level (SPL), Sound Power, and other Octave or Narrow Band measurements. You can also display acoustic and vibration shapes together on the same model, thus making it easier to visualize structure-borne noise problems. Basic Modal Analysis Option This option estimates modal parameters (frequency, damping, and mode shape) by curve fitting a set of measurements using FRF-based curve fitting methods. It includes several types of mode indicator functions for counting resonance peaks, plus several different curve fitting methods, including the SDOF (Single Degree of Freedom) Peak and CoQuad methods, and the MDOF (Multi Degree of Freedom) Orthogonal Polynomial method. It also includes a mode shape Comparison display for comparing two mode shapes in animation, Frequency Response Function (FRF) Synthesis from modal parameters for comparison with experimental data, the Modal Assurance Criterion (MAC) calculation for numerically correlating two mode shapes, a Complexity plot for examining complex modes, shape Normalization for converting complex to normal mode shapes, and more.
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Tutorial Volume IA - Basic Operations Multi-Reference Modal Analysis Option This option includes all of the features of the Basic Modal Analysis option, plus several advanced multiple reference curve fitting methods for identifying closely coupled modes and repeated roots. It also includes the Stability diagram and Poles diagram; more powerful graphical methods for finding stable pole estimates from a set of multi-reference measurements. Operational Modal Analysis (OMA) Option For cases where only operating (or output only) responses are acquired and the excitation forces are not measured, modal parameters can still be extracted from a set of specially processed Fourier Spectra, Cross spectra or ODS FRFs using FRF-based curve fitting methods. This option adds special features to the Multi-Reference Modal Analysis Option. It provides a complete set of capabilities for extracting modal parameters from measurements made in any type of testing environment. Multi-Input Multi-Output (MIMO) Modeling & Simulation Option This option uses MIMO modeling to calculate the following; •
Structural responses due to excitation forces (Outputs due to Inputs)
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Excitation forces due to responses (Inputs due to Outputs)
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Multiple-reference FRFs (calculated from Multiple Inputs and Outputs)
Using a MIMO model, time or frequency domain responses can be calculated from multiple forces, force path analysis can be done using measured responses, and MIMO FRFs together with Multiple & Partial Coherence can be calculated from excitation and response time waveforms, or Auto & Cross spectra. Structural Dynamics Modifications (SDM) Option This option allows you investigate how physical changes to a machine or structure affect its modes of vibration. Physical changes are modeled by adding FEA elements (springs, masses, dampers, rods, bars, plates, and solid elements), to a structure model. SDM also allows you to model the effects of adding tuned vibration absorbers (mass, spring, dampers), to a structure. The SDM option also supports sub-structuring, calculating the affects of connecting two or more structures together using FEA elements. This option also includes Modal Sensitivity, the ability to examine how sensitive its modes are to the amount of physical modification to a structure. Experimental Finite Element Analysis (FEA) Option This option allows you to add FEA elements to an experimental 3D structure model, and calculate the analytical modes of a structure from its FEA model. It contains a library of industry standard finite elements, including linear and rotational masses, springs, and dampers, plus rods, bars, plates, and solid elements. It also includes the FEA assistant for quickly populating a structure model with finite elements. Mode shape expansions are also calculated from the FEA model and experimental data. FEA models can be imported and exported in several popular FEA file formats, including the NASTRAN format. FEA Model Updating Option This option evaluates 1000's of mode shape solutions due to changes in the physical properties of an FEA model, and orders the solutions according to how closely the FEA modes match a set of experimental modes. FEA property changes include mass, spring, and damper changes, rod element cross sectional areas, beam element cross sectional areas and inertias, plate element thicknesses and solid material properties (elasticity, Poissons ratio, & density). All solutions can be examined both numerically and graphically.
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Overview Direct Data Acquisition Options With any one of its Direct Data Acquisition options, you can directly control and acquire data from a broad range of third party multi-channel data acquisition hardware front-ends. These options all operate from the a uniquely designed Acquisition window, from which you set up the front end, acquire data, and calculate various multi-channel frequency domain based functions, such as Auto & Cross spectra, FRFs, and Coherences. Impact testing, multi-shaker testing, and acquisition of operating data are supported. The graphical user interface includes a connection to a structure model, where an entire test can be set up beforehand by selecting test points & directions. As measurements are acquired during a test, they can be accumulated into a separate Data Block for further post-processing. ODS animation on a 3D model can also be initiated directly from this window, even during a test. Program Option This option allows you to create a program in ME'scope as a sequence of ME'scope commands. Each row of a Program spreadsheet contains an ME'scope window name and the command to be executed in that window. Every ME'scope command can be executed from a Program. This option is useful for performing repetitive tasks in ME'scope, such as continuous monitoring applications or processing multiple sets of data.
Types of Measurements Imported Every ME’scopeVES package can import multi-channel data from a wide variety of third party data files. File formats used by all popular multi-channel data acquisition systems, analyzers, recorders, and data collectors are supported. Over 45 different file formats are supported, including ASCII text spreadsheet, MATLAB, DADiSP, Microsoft WAV, and Universal File Format (UFF). ME'scope can import most of the popular kinds of time or frequency domain measurement functions. The following types of measurement functions are recognized by ME'scope. Time Domain Functions •
Time Waveform (vibration, sound pressure, strain gauge, temperature, etc.)
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Auto Correlation
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Cross Correlation
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Impulse Response Function (IRF)
Frequency Domain Functions •
Fourier Spectrum (FFT of a sampled Time Waveform)
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Auto Spectrum
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Cross Spectrum
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Power Spectral Density (PSD)
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Frequency Response Function (FRF) (Response / Force)
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Transfer Function (Output / Input)
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Transmissibility (Roving response / Reference response)
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Coherence (Ordinary, Multiple & Partial)
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ODS FRF (Roving response Auto Spectrum & phase relative to a Reference response)
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Acoustic Intensity
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Sound Pressure Level
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Tutorial Volume IA - Basic Operations Order Tracked Responses ME'scope can import Order Tracked responses, either as functions of time or machine RPM. A set of these measurements taken from an operating machine can be used to display order tracked ODS's, also called running modes.
Time-Based ODS Animation With ME'scopeVES, you can animate time-based Operating Deflection Shapes (ODS's) directly from multi-channel data that was acquired spatially from a machine or structure. •
Time-domain Sweep Animation is done by automatically sweeping a cursor through a set of time histories.
You can stop the animation, back it up, and play it forward to observe in slow motion vibration phenomena that may have taken place very quickly in real time. For example, you can observe in slow motion the run up, coast down, or other transient behavior of a machine. During this transition period, the machine may pass through a variety of vibrational states, due to resonances, unbalances, varying loads, fluid flow, etc.
Sweep Animation from Multi-Channel Time Responses.
Frequency-Based ODS Animation With ME'scopeVES, you can animate frequency-based ODS's (Operating Deflection Shapes) directly from data that was acquired from a machine or structure •
During Sine Dwell animation, the ODS at a specific frequency is displayed using sinusoidal modulation.
A frequency-based ODS allows you to see how a structure behaves at a single frequency. While dwelling at a frequency, the ODS will show you where vibration levels are highest, and will indicate loose parts and connections. A frequency-based ODS can also help you determine whether or not a resonance is being excited, or whether the vibration is an order related forced vibration.
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Overview
Sine Dwell Animation of an ODS Near a Resonance.
Mode Shape Animation Modes of vibration are used to characterize resonant vibration in machinery and structures. •
All structures have specific natural frequencies at which they readily absorb energy.
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When a resonance is excited, it can cause excessive noise and vibration, resulting in premature structural failures.
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Each resonance, or mode of vibration, is defined by its natural frequency, damping, and mode shape.
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At or near a modal frequency, the response of a structure is usually dominated by the resonance.
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A frequency-based ODS will often look like the mode shape of a nearby resonance, but not always.
However, mode shapes, along with their frequency and damping values, are more accurately obtained by curve fitting a set of FRF measurements, or a set of Fourier spectra, Cross spectra or ODS FRFs calculated from operating data.
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Tutorial Volume IA - Basic Operations
Sine Dwell Animation of a Mode Shape.
Documentation with Digital Movies™ ME'scopeVES contains a Digital Movies™ feature with which you can record and play back any shape animation. •
A Digital Movie is a sequence of animation frames saved into a Microsoft Windows WMV file.
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Digital Movies can be played on any computer that can play WMF files.
You can send Digital Movies to your clients, and they can view the animation just as it appears in ME'scopeVES. Digital Movies can also be embedded in Microsoft Power Point presentations or Word documents, and played by clicking on them. Individual frames can be cut from a movie and pasted into documents, or annotations added to frames with a graphics or text processor.
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Overview
Digital Movie Showing Automotive Mode Shapes.
How the Operating Manual is Organized The complete operating manual consists of two Volumes in four parts, 1. Volume IA contains Tutorials of Basic operations 2. Volume IB contains Tutorials of Optional operations 3. Volume IIA is the Command Reference of Basic operations 4. Volume IIB is the Command Reference of Optional operations Installation This chapter describes the hardware and software requirements for running ME'scope. It also has instructions for installing the ME'scope software on your computer, and for installing and testing the hardware Security Key if your software has one. Tutorials The chapters in Volume I show you by example how to use many of the features in ME'scope. The Tutorial topics are presented in the order in which you would normally encounter them when using ME'scope. If you are a first time user, read through these Tutorials and perform the example exercises to gain a better understanding of the uses of ME'scope. Volume IA - Basic Operations •
Introduction to ME'scope
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Building and Animating a Plate Model
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Drawing Structure Models
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Importing Measurement Data
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Displaying Shapes in Animation
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Tutorial Volume IA - Basic Operations •
Documenting Results
Volume IB - Options •
Signal Processing
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Basic Modal Analysis
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Multi-Reference Modal Analysis
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Operational Modal Analysis (OMA)
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Multi-Input Multi-Output (MIMO) Modeling & Simulation
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Acoustics
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Direct Data Acquisition
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Structural Dynamics Modification (SDM)
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Experimental Finite Element Analysis (FEA)
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FEA Model Updating
Command References The chapters in Volume II document all of the commands in each ME'scope window. Each ME'scope Option enables additional commands in one or more ME'scope windows. Command descriptions are ordered by command menu, from left to right in a window, and then by the commands in each menu, from top to bottom. Volume IIA - Basic Operations •
ME'scope Window commands
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Structure Window commands
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Data Block Window commands
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Shape Table Window commands
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Report Window commands
Volume IIB - Options •
Acquisition Window commands
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Program Window commands
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Signal Processing commands
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Basic Modal Analysis commands
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Multi-Reference Modal Analysis commands
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OMA (Operational Modal Analysis) commands
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Acoustics commands
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MIMO Modeling & Simulation commands
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SDM commands
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Experimental FEA commands
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FEA Model Updating commands
Help Windows All of the material in the Operating Manual is also contained in the Tutorial & Command Help Windows in ME'scope.
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Overview •
The Help windows can be opened at any time, and left open during the operation of ME'scope.
The Help windows contain tabs for Table of Contents, Index, Search, and Glossary. Table of Contents A tree-view of all help topics organized by main headings with indented sub-headings Index A list of pre-defined keywords, •
Double-click on a keyword to display links to all topics relevant to the keyword.
Search Lists links to all topics which contain a user-specified keyword. Glossary A definition of words and terms used in ME'scope.
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Installation Computer System Requirements To use ME'scope, your computer must have at least the following capabilities; •
Microsoft Windows XP, Windows Vista, Windows 7, or Windows 8 with the latest Service Pack installed. •
Both x86 (32 bit) and x64 (64 bit) versions of Windows are supported.
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A computer with a 1 Gigahertz (GHz) or faster microprocessor.
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At least 1 Gigabyte (GB) of RAM memory.
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A hard disk with at least 3 Gigabytes (GB) of available space.
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A mouse or other pointing device.
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Microsoft DirectX 9.0c compatible graphics hardware. (If running a virtual Windows system on an Apple or Linux computer, the Windows system must support DirectX 9.0c hardware acceleration.)
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Microsoft .NET Framework 3.5 software.
NOTE: If required, the .NET Framework 3.5 software is installed during ME'scope installation.
Installing the Software NOTE: ME'scope cannot be run from its installation CD ROM or over a network. It must be installed on a computer hard drive to run it. Installing from the Installation CD ROM •
All of the files necessary to install ME'scope on your computer are included on the Installation CD ROM.
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Verify that your computer hard disk has at least 3 GB of free space.
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Terminate all other programs before starting the ME'scope installation.
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Insert the Installation CD ROM into the CD ROM drive of your computer.
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If AUTORUN is enabled in Windows, the Installation window will open, as shown below.
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Or, open the Windows Explorer, display the CD ROM drive contents, and double click on MEscopeVES_Setup.EXE.
Installing Software Downloaded from the Internet •
Place the MEscopeVES_Setup.EXE program in the same folder at your VESxxxxx.vtl License file.
•
Double click on MEscopeVES_Setup.EXE.
Running the Installer Program MEscopeVES_Setup.EXE
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Tutorial Volume IA - Basic Operations
ME'scope Installation Dialog Box. •
Click on Next > to begin the installation.
The License Agreement dialog box will be displayed. •
Check the check box in front of "I agree to these terms and conditions", and click on the Next > button.
The following dialog box will open. •
Browse for a different Installation folder if necessary, and click on the Install button.
ME'scope Installation Options Dialog. After the ME'scope software has been installed , the following ME'scope Examples dialog box will open.
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Installation
Begin Examples Installation dialog box. •
Click on the Next > button to open the following dialog box.
•
Check all of the Examples files that you want installed, and click on the Install button.
ME'scope Examples Installation dialog box. When all of the checked Example files have been installed, the following dialog box will open. •
Click on the Finish button.
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Tutorial Volume IA - Basic Operations
ME'scope Installation Completed dialog box. Volumes I and II of the Operating Manual in Adobe Acrobat (PDF) format were also copied from the Installation CD ROM onto your hard drive. •
A link to each manual is included under ME'scope in the Windows Start menu.
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These documents can be viewed with an Adobe Acrobat reader.
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Each volume is divided into two documents to separate the Basic from the Optional functions.
•
See How the Operating Manual is Organized) in the Overview chapter.
The Security System A complete ME'scope installation consists of the following three parts; •
The ME'scopeVES.EXE program and other software files.
•
A Hardware Security Key, or Vibrant License Server software.
•
An ME'scope license file named VESxxxxx.vtl, where xxxxx is your unique license number.
•
For example, if your license number is 12256, the license file will be named VES12256.vtl.
If ME'scope Won't Run If you get an error message when you attempt to execute ME'scopeVES.EXE, it could be due to one of the following; •
The Hardware Security Key or the Vibrant License Server software is not properly installed and functional.
•
The License file VESxxxxx.vtl is missing or corrupted.
•
The VESxxxxx.vtl license file does not contain your unique license number.
•
The ME'scopeVES.EXE software is corrupted.
After checking the above items and reinstalling the software, if ME'scopeVES still does not run •
16
Contact Vibrant Technology for assistance.
Installation Help | About Box •
The license file VESxxxxx.vtl authorizes the operation of the ME'scopeVES Package & Options that you purchased.
•
Execute Help | About in the ME'scopeVES window to open the following About box, which lists the Package & Options authorized by your license file VESxxxxx.vtl.
About Box.
Registering for User Support NOTE: You must register for User Support in order to download software & documentation updates from the Vibrant Internet site. To register for User Support, •
Go to the Vibrant Internet site www.vibetech.com .
•
Select Support from the horizontal menu across the top of the page. The User Support page will be displayed.
•
Click on "Click here to Register", complete the form, and press the Register>> button.
You now have access to portions of the Vibrant Internet site that are only available to registered users with active User Support.
17
Introduction to ME'scope Projects, Data Files, and Windows All work in ME'scope is done in the currently open Project file. NOTE: Only one Project file can be open at a time in ME'scope. A Project file (with file name extension .VTprj) can contain one (or more) of the following data files, •
Structure (STR) file
•
Data Block (BLK) file
•
Shape Table (SHP) file
•
Acquisition (ACQ) file
•
Report (RTF) file
•
Program (PGM) file
•
Added files
All of the data in these files is contained within the Project file on disk, except Added files. Added files are stored separately on disk, and are opened from a separate application program. ME'scope Window When ME'scope is running, the ME'scope (main) window is always open.
ME'scope Window. Data File Windows
19
Tutorial Volume IA - Basic Operations •
A separate window is used to display and manipulate the contents of each data file within the currently open Project.
•
When a data file is opened, a copy of its contents on disk is put into RAM memory and displayed in its own window. •
An STR file is displayed in Structure window.
•
A BLK file is displayed in a Data Block window.
•
An SHP file is displayed in a Shape Table window.
•
An ACQ file is displayed in an Acquisition window.
•
An RTF file is displayed in a Report window.
•
A PGM file is displayed in a Program window.
ME'scope with a Structure (STR) and Data Block (BLK) Window Open. Saving Data Files •
When a file is saved in ME'scope, its file contents in RAM memory replace the contents of the file in its (VTprj) file stored on disk.
•
If a Project is closed without saving changes to one of its data files, the contents of that file on disk will not be changed.
Mouse Operations Many operations in ME'scope require the use of the Windows mouse. Commonly used mouse operations include; •
Pointing, clicking, dragging, and rotation using the left mouse button.
•
Zooming and scrolling using the mouse wheel.
•
Displaying context menus using the right mouse button.
Other special mouse operations are performed in each data file window.
20
Introduction to ME'scope •
See the beginning of each Window Commands chapter for special mouse operations pertaining to that window type.
NOTE: To enlarge this text, click on it, hold down the Ctrl key and spin the mouse wheel.
Window Operations More than one data file window is open at a time during the use of ME'scope. Learning how to open, close, move, arrange & re-size windows is important for effectively displaying them together in the Work Area. Center a Window in the Work Area •
Execute Display | Center Window
in the upper left corner of the window.
Center the ME'scope Window on the Desktop •
Execute Window | Arrange | Center
in the upper left corner of the ME'scope window.
Make a Window Active •
Click anywhere within the window.
•
(The title bar of the active window is darkened or colored.)
Move a Window •
Position the mouse pointer over the title bar (on the top of the window), and click & drag the window to the desired position.
Re-size a Window •
Hover the mouse pointer over one of its edges so that the mouse pointer changes to a double arrow.
•
Then click & drag the edge.
Close a Window •
Click on the close button
in the upper right corner of the window.
Maximize a Window •
Click on the maximize
button in the upper right corner of the window.
Minimize (Icon) a Window •
Click on the minimize
button in the upper right corner of the window.
Restore a Minimized Window •
Double click on its Icon in the Work Area.
•
Or double click on its file name in the Project Panel.
•
Or click on its file name in the Window menu in the ME'scope window.
Tool Tips Each command in ME'scope has a Tool associated with it.
21
Tutorial Volume IA - Basic Operations •
A Tool is a graphical button that accompanies the command in its menu, and can be added to a Toolbar in the window.
•
A Tool Tip is a brief description of a command (typically its menu location and name).
Help | Show Tool Tips When this command is checked, the display of Tool Tips is enabled. •
Click on a window to make it active.
•
Hover the mouse pointer over any Tool on a Toolbar to display its Tool Tip.
Structure Window Showing a Tool Tip.
Command Toolbars A Toolbar contains Tools of the menu commands for a window. NOTE: Menus and Toolbars can be displayed differently by choosing one of the options on the Display tab in the Project | ME'scope Options box. •
Each window will open with one or more default Toolbars, each containing commonly used commands on it.
•
Any menu command can be added to a Toolbar in its own window.
•
Command Tools can be added to an existing Toolbar, or a new Toolbar can be created.
•
Toolbars can be floated or attached to one of the four sides of each window in ME'scopeVES.
Moving a Toolbar •
Place the mouse pointer over the beginning area
on the (left or top) of the Toolbar.
The mouse pointer will change to crossed arrows. •
Drag & drop the Toolbar to anywhere inside or outside of the window.
Customizing Toolbars •
22
Position the mouse pointer in the menu or the Toolbar area, right click, and execute Customize from the context menu.
Introduction to ME'scope
•
Or click on the More Tools command Tools | Customize.
at the end of a Toolbar, and execute Add or Remove
The Toolbar Customize dialog box will open, as shown below
Toolbar Customize Dialog Box. Adding a Tool to a Toolbar •
Open the Customize dialog box.
•
Click on the Commands Tab in the Customize dialog box. •
All of the menus for the window will be displayed in the Categories list.
•
Click on the menu name in the Categories list to display all of the commands in that menu.
•
Click & drag a Tool from the Commands list onto the Toolbar (until an I beam is displayed), and drop it.
Move a Tool to Another Toolbar •
Open the Customize dialog box.
•
Click & drag it from the Toolbar and drop it onto another Toolbar.
Reposition a Tool on a Toolbar •
Open the Customize dialog box.
•
Click & drag it from its position and drop it in its new position on the Toolbar.
Remove a Tool from a Toolbar •
Open the Customize dialog box.
•
Position the mouse pointer on the Tool and click & drag it off the Toolbar.
Create a New Toolbar •
Open the Customize dialog box.
•
Click on the New button in the Customize dialog box.
•
Enter the name of the new Toolbar in the dialog box that opens.
•
The new Toolbar is displayed in the Toolbar area at the top of the window.
23
Tutorial Volume IA - Basic Operations Locking the Toolbars •
Right click in the menu or the Toolbar area, and execute Lock the Toolbars.
•
If Lock the Toolbars is checked, the Toolbars are locked in position.
Hidden Floating Toolbars Floating Toolbars will become hidden behind other windows whenever their window is not the active window. •
To make floating Toolbars visible, click anywhere on the window to make it active.
Resetting the Toolbars •
Execute File | Options in the ME'scopeVES window to open the Options dialog box.
•
On the Display tab, press Toolbars in the Clear User Settings section.
The ME'scope Window The ME'scope window is always open when ME'scope is running. •
Click on its close button
to terminate the operation of ME'scope.
The ME'scope window contains a Command Menu, a Toolbar, a Project tab and Demos tab, all normally located at the top of the window, as shown below. The Work Area is located in the center, and the Status Bar is located at the bottom of the window, as shown below. Project Fly-Out Panel The Project fly-out panel contains two panes, separated by a moveable red splitter bar. One pane lists the data files in the currently open Project file, and the other pane lists the Project (VTprj) files in the current disk folder. •
24
Hover the mouse pointer over the Project tab to display the Project fly-out Panel.
Introduction to ME'scope ME'scope Window. Work Area The center of the ME'scope window is called the Work Area. All data file windows in the currently open Project are opened inside the Work Area. •
Execute one of the commands in the Window | Arrange Windows menu to arrange all of the windows in the Work Area.
•
Execute Display | Center Window Work Area.
in the upper left corner of a window to center it in the
Project Folder Tabs In addition to the Project tab, several default Project Folder tabs are added to the ME'scope window when it is installed. Hovering the mouse over a Project Folder Tab will open the fly-out panel containing all of the ME'scope Projects in that folder. Opening a Project From a Folder Tab •
Hover the mouse pointer over one of the tabs at the top of the ME'scope window to open its flyout panel.
•
Hover the mouse pointer over each Project thumbnail (picture) on the panel to display its name.
•
Double click on any Project in a fly-out panel to open the Project.
•
Move the mouse pointer off of a fly-out panel to close it.
ME'scope Window Showing Demos Folder fly-out panel. Moving a Fly-out Panel •
Hover the mouse pointer over a Folder Tab to open its fly-out panel.
•
Click on the pin icon in the upper right corner to pin the fly-out panel open, as shown below.
25
Tutorial Volume IA - Basic Operations
Pinned Folder fly-out panel. •
Drag the pinned fly-out panel into the middle of the Work Area.
Notice that four arrow icons appear near the top, bottom & sides of the Work Area. •
Drag the pinned fly-out panel onto an arrow icon to attach it to the top, bottom or a side of the Work Area.
•
Click on the pin icon again in the upper right corner to un-pin the fly-out panel.
Creating a New Folder Tab Any Folder of Project files on your computer disk can be added as a fly-out panel to the ME'scope window. •
Hover the mouse pointer over the Project tab to open its fly-out panel.
•
Right click on a Folder in the (right or bottom) pane in the Project fly-out panel.
•
Select Show Folder as Tab from the menu.
Right Click To Create a New Folder Tab.
Opening a Project •
26
Hover the mouse pointer over the Project tab to display the Project Fly Out Panel.
Introduction to ME'scope
ME'scope Window With the Project Fly Out Tab Displayed. Opening a Previously Saved Project file There are several ways to open a previously saved Project; •
Execute File | Project | Open in the ME'scope window.
•
Select the Project from the list of Recent Projects in the Start Page window.
NOTE: The Start Page is displayed when no Project is currently open. •
Double click on the Project file name in the (right or lower) pane of the Project fly out panel.
•
Right click on the file in the (right or lower) pane of the Project Fly Out Panel, and select Open from the context menu.
Creating a New Project •
Execute Project | New in the ME'scope window.
Creating a New Data File •
Execute one of the commands in the File | New menu in the ME'scope window.
Adding a File from Another Project •
Double click on the file from another Project in the (right or lower) pane of the Project fly out panel.
•
Or right click on the file in the (right or lower) pane of the Project fly out panel, and select Add from the context menu.
Importing a Data File •
Execute one of the commands in the File | Import menu in the ME'scope window.
Structure (STR) Window 27
Tutorial Volume IA - Basic Operations A Structure (STR) file contains a 3D geometric model of a test machine, test structure, or acoustic surface on which shape data is displayed in animation. •
A structure model is defined using Points, Lines, and Surfaces.
A Structure window is used for several purposes; •
Drawing a 3D model of a test machine or structure.
•
Displaying shapes in animation (ODS's, mode shapes, acoustic shapes, or engineering data shapes.
•
Creating an FEA model by attaching FEA elements to the geometric model, and executing SDM, Experimental FEA, and FEA Model Updating commands on the FEA model.
•
Graphical control of data acquisition in an Acquisition window.
Adding a Structure Model to a Project There are several ways to add a structure model to a Project; •
Execute File | Import | Structure, and import the model from an external source such as a CAD program or spreadsheet file.
•
Double click on a Structure (STR) file in the (right or lower) pane of the Project Fly Out Panel.
•
Right click on a Structure (STR) file in the (right or lower) pane of the Project Fly Out Panel, and select Open from the menu.
To create a new structure model in a Project; •
Execute File | New | Structure in the ME'scope window, and create the model using the drawing tools in the new Structure window.
Structure Window in Draw State.
Data Block (BLK) Window
28
Introduction to ME'scope A Data Block (BLK) file contains one or more time or frequency domain measurements. •
Each measurement in a Data Block is called a Trace.
•
All of the Traces in a Data Block have the same time or frequency axis values.
Time-based or frequency-based ODS's, mode shapes, acoustic shapes, or engineering data shapes are interactively displayed on the structure model in a connected Structure window, using Trace values at the cursor position in a Data Block window. Adding a Data Block to a Project There are several ways to add a Data Block to a Project; •
Execute File | Import | Data Block, and import measurements from a third party data file.
•
Double click on a Data Block (BLK) file in the (right or lower) pane of the Project Fly Out Panel.
•
Right click on a Data Block (BLK) file in the (right or lower) pane of the Project Fly Out Pane, and select Open from the menu.
There are several ways to create a new Data Block in a Project; •
Execute File | New | Data Block in the ME'scope window, and create a Data Block with synthesized time domain Traces in it.
•
Use an Acquisition window to acquire measurements from a third party acquisition front end, and save them into a Data Block.
Data Block Window Showing Four Traces in Row-Column Format.
Shape Table (SHP) Window A Shape Table (SHP) file contains multiple shapes. Shapes can be displayed in animation directly from a Shape Table on the structure model in a connected Structure window. •
A "shape" is any data from two or more measurements from different test points or DOFs on the machine, structure or acoustic surface.
•
Common types of shapes are Operating Deflection Shapes (ODS's), mode shapes, acoustic shapes, and engineering data shapes.
29
Tutorial Volume IA - Basic Operations A Shape Table (SHP) file is used in a variety of different ways; 1. Save it from a Data Block window during animation or curve fitting. 2. Save it from an SDM, Experimental FEA, or FEA Model Updating calculation. 3. Save it from a Forced Sinusoidal Response calculation in a Data Block or Shape Table window. 4. Import it from a third party disk file. 5. Create a new Shape Table, and Manually enter data into it. Adding a Shape Table to a Project There are several ways to add a Shape Table to a Project; •
Execute File | Import | Shape Table, and import shapes from a third party data file.
•
Double click on a Shape Table (SHP) file in the (right or lower) pane of the Project Fly Out Panel.
•
Right click on a Shape Table (SHP) file in the (right or lower) pane of the Project Fly Out Panel, and select Open from the menu.
There are several ways to create a new Shape Table in a Project;
30
•
Execute File | New | Shape Table in the ME'scope window, and manually enter or paste data into its Shape and DOFs spreadsheets.
•
Execute Curve Fit | Shapes | Save Shapes to save mode shapes from FRF-based curve fitting in a Data Block.
•
Execute Tools | Save Shapes to save the ODS at the cursor position in a Data Block or Acquisition window.
•
Press the Save Shape button in the Transform | MIMO | Sinusoidal ODS dialog box, opened from a Data Block.
•
Press the Save Shape button in the Tools | Sinusoidal ODS dialog box, opened from a Shape Table with mode shapes in it.
Introduction to ME'scope
Shape Table Containing 10 Mode Shapes.
Time-Based ODS Demo •
Hover the mouse pointer over the Demos tab to display the Demos Fly Out Panel.
•
Make sure the Help | Show Tool Tips is checked.
•
Position the mouse pointer over the panel to display the Antenna.VTprj Project name, and double click to open the Project.
Demos Tab With Mouse Over Antenna.VTprj.
31
Tutorial Volume IA - Basic Operations The Project will open and Sweep Animation will begin using shape data from a Data Block on the left with four Traces in it. Notice that a Line cursor (vertical red line) is sweeping through the Traces in the Data Block window. The model is being deformed by the ODS (Trace data) at the cursor position. Changing the Animation Speed The animation may be too fast or too slow, depending on the speed of your computer. To change the animation speed, •
Click on the Structure window Title bar to make it active.
•
Hover the mouse pointer over the Structure window Toolbar to display the Tool tips.
•
Locate the Animate | Speed | Increase Speed (rabbit) and Animate | Speed | Decrease Speed (turtle) Tools on either side of the Animation Method Tools
•
.
Click on the Turtle Tool to decrease the animation speed. Click on the Rabbit Tool to increase the speed.
Time-Based ODS Demo Showing Sweep Animation. Quad View versus Single View The Structure window can display a single View of the structure model, or four Views together in a Quad View format. 1. 3D View (upper right quadrant). 2. Z Axis View (upper left quadrant). 3. X Axis View (lower left quadrant). 4. Y Axis View (lower right quadrant). NOTE: When the Vertical Axis is changed on the Display tab in the Structure File | Options box, the labeling of the three 2D Views will also change. To change between the Quad View and one of the four Views, •
Double click on the single View to display the Quad View.
•
Double click on a single View in the Quad View to display that View.
Active View
32
Introduction to ME'scope When the Structure window is in Quad View, the active View is indicated by the yellow box in the Display | View button. •
Click on a View to make it active.
•
When the 3D View is active the upper right quadrant of the Display | View button is yellow
•
.
In Quad View, click on each View to make it the active View turns yellow on the Display | View Tool.
Zoom •
Click in a View to make it active, and spin the mouse wheel to Zoom the structure in that View.
Pan •
Hold down the Shift key and drag the mouse to Pan the structure model in the active View.
Rotation in the 3D View •
Click & drag in the 3D View to rotate the structure.
Interpolated Motion The deformation of the Antenna structure model is being created using data from only four Traces in the Data Block window. Without interpolation, only these four points (the numbered points on the 3D model) would be the only ones moving during animation. Most of the points on the model are unmeasured points, but they are moving also. The motion of the unmeasured points is being interpolated from the motions of nearby measured points. •
Execute Animate | With Interpolation enable interpolation.
several times in the Structure window to disable and
Notice that with interpolation enabled, the cantilevered motion of the model is influenced by of the motions of the four Measured DOFs plus the influence of Fixed DOFs at the base of the antenna.
Frequency-Based ODS Demo •
Hover the mouse pointer over the Demos tab to display the Demos fly out panel.
•
Make sure the Help | Show Tool Tips is checked.
•
Move the mouse pointer over the Demos panel to display the Jim Beam.VTprj Project name, and double click to open the Project.
The Project will open in Sine Dwell animation using shape data from a Data Block with 99 FRFs in it. Notice that the Line cursor (vertical red line) is positioned in the middle of the Data Block Traces. The 3D model is being animated with the ODS (data from each Trace) at the cursor position. Sinusoidal modulation of the ODS is used to create the sine dwell animation. •
To view each of the FRF measurements, drag the vertical scroll bar on the right side of the Trace graphics area in the Data Block window.
Animating Near a Resonance The peaks in the FRF measurements are evidence of structural resonances, or modes of vibration. At or near a resonance peak, the ODS (values of the FRFs) is being dominated by the mode shape
33
Tutorial Volume IA - Basic Operations associated with the resonance. For lightly damped structures, the ODS at or near a resonant frequency will closely approximate the mode shape. To view the ODS at a resonance, •
Execute Format | Overlay Traces to display all FRFs overlaid on one another.
•
Execute Display | Imaginary
•
Click & Drag the Line cursor in the Data Block window until it lies on or near one of the resonance peaks.
to display the Imaginary parts of the FRFs in Overlaid format.
At one of the lower frequency resonance peaks, the ODS on the structure model should look like a bending or torsional mode shape of the structure. •
Click & Drag the Line cursor to another peak, and notice how the ODS changes.
Animation at a Resonance Peak. Trace Display Formats There are several different formats for displaying Traces in the Data Block window. To display Traces in a Row/Column format, •
34
Execute Format | Rows/Columns in the Data Block window. A graphical array of rows & columns will be displayed below the command.
Introduction to ME'scope
Data Block window with Rows & Columns selection box. •
To display 2 rows and 2 columns, choose 2,2 from the array of rows & columns.
•
Try the other commands Strip Chart, Cascade or Contour Map in the Format menu.
Mode Shape Demo •
Hover the mouse pointer over the Demos tab to display the Demos fly out panel.
•
Make sure the Help | Show Tool Tips is checked.
•
Move the mouse pointer to display the I-Beam.VTprj Project name, and double click to open the Project.
The Project will open with Sweep animation in the Structure window displaying mode shapes for a Shape ) Table. Notice that one of the Select Shape buttons is depressed (a green box and "Yes" text in the (upper) Shapes spreadsheet in the Shape Table window on the right. This is the mode shape currently being displayed in animation on the structure model. The currently displayed mode shape will automatically increment because Sweep Animation is enabled. •
Execute Animate | Method | Sine Dwell Sine Dwell.
•
Click on a different Select Shape in animation.
to change the animation from Sweep to button in the Shapes spreadsheet to display its shape
Contour Colors Many display functions in the Structure window toggle between checked (meaning they are enabled) and un-checked (meaning they are disabled). Contour colors can be displayed on structure model surfaces to show areas of high versus low shape values. The colors used for the color contour map are specified in the File | Options box of the Animation Source window, in this case the Shape Table window. •
Execute Animate | Contours | Contour Colors colors on the surfaces of the structure model.
in the Structure window to display contour
35
Tutorial Volume IA - Basic Operations
•
Execute Animate | Contours | Contour Colors
again to disable the contour fill display.
Mode Shape Animation Showing Contours.
Acoustic Intensity Demo •
Hover the mouse pointer over the Demos tab to display the Demos fly out panel.
•
Make sure the Help | Show Tool Tips is checked.
•
Move the mouse pointer to display the Intensity.VTprj Project name, and double click to open the Project.
The Project will open and Sweep animation will begin from a Data Block of Acoustic Intensity measurements from a speaker. Notice that acoustic Trace data is displayed in an octave band format (1/3 octave in this Data Block), and that a Line cursor (vertical red line) is sweeping through the Traces in the Data Block window. The color contours on the acoustic surface in front of the speaker are indicating levels of intensity at the cursor position. Arrows are also being displayed to indicate the magnitude and direction of the acoustic intensity.
36
Introduction to ME'scope
Acoustic Intensity Animation.
Digital Movie Demo A Digital Movie is a sequence of animation frames saved into a Microsoft Windows WMV file. The commands in the Movie Menu in the Structure window are used to create Digital Movies of any animated display in the Structure window. Digital Movies are played back using the Windows Media Player. •
Hover the mouse pointer over the Demos tab to display the Demos fly out panel.
•
Move the mouse pointer to display the Corvette.VTprj Project name.
•
Double click to open the Movie Demo Project.
•
On the Project panel under Added Files, double click on ADF: Corvette.AVI
37
Tutorial Volume IA - Basic Operations
Demo Digital Movie Window.
38
Tutorial #1 - Frequency-Based ODS Animation Plate Model In this tutorial, we will build a model of a flat plate and display frequency-based ODS data in animation on the model. video NOTE: When an ODS is displayed near a resonant peak in a set of FRFs, it is usually dominated by the resonance and is therefore a close approximation of the mode shape associated with the resonance. The following steps will be carried out to display the mode shapes of the flat plate; 1. Create a model of the test article with all of its test points included. 2. Import FRF measurements taken from the test article into a Data Block file. 3. Create Animation equations by assigning the FRF measurements (M#s) to DOFs (points & directions) on the model where the measurements were made. 4. Display ODS's in animation on the plate model from the cursor position in the FRFs. 5. Position the cursor at a resonance peak to display an approximation of the mode shape for that resonance.
Animating an ODS at a Resonance Peak. •
Execute the File | Project | New command to start a new Project.
•
Enter "Flat Plate Test" into the File name field in the dialog box, and press the Save button.
39
Tutorial Volume IA - Basic Operations This will clear all data from the computer memory and display the ME'scope window with an empty Work Area.
Step 1. Drawing the Plate Model 3D structure models are easily built in ME'scopeVES by using the Drawing Assistant. Complex models can be created by using several simpler geometric structures, called SubStructures. •
Execute Project | New to open a new Project file.
•
Execute File | New | Structure.
•
Type Plate Model into the dialog box, and press OK.
•
A new (empty) Structure window will open.
Coordinate Units NOTE: It is only necessary to create a structure model that looks like the test article. A dimensionally correct model is only required when using SDM, Experimental FEA or FEA Model Updating commands. The desired Length units for the structure model are entered using the File | Structure Options box, •
Execute File | Structure Options in the Structure window to open the Options dialog box.
•
On the Units tab, choose the desired Length units, and click on OK.
Using the Drawing Assistant The horizontal plate model will be built by modifying one of the editable SubStructures from the SubStructure library, which is accessed from the Drawing Assistant. •
Execute Draw | Drawing Assistant tabs.
in the Structure window to display the Drawing Assistant
Since the Structure window currently has no Substructures in it, only the SubStructure tab is enabled. •
On the SubStructure tab, scroll the browser to find the Editable Plate SubStructure, and double click on it.
A plate SubStructure will be added to the SubStructures spreadsheet, and also displayed in the graphics area of the Structure window. This editable SubStructure will be re-defined as a grid of Points spaced 10 length units apart, with 5 points in the Global X direction and 6 points in the Global Y direction.
40
•
On the Dimensions tab, enter Width (in Length units) = 50 , and Points = 6, as shown below.
•
Enter Height (in Length units) = 40, and Points = 5, as shown below.
Tutorial #1 - Frequency-Based ODS Animation
Vertical Plate with 6 by 5 Grid of Points. Next, the plate will be rotated from its vertical position to a horizontal position in two increments of 45 degrees each. •
On the Position tab, enter 45 into the Degrees box.
•
Choose Global coordinates, and press the Y up arrow in the Rotate area twice.
•
On the SubStructures spreadsheet, change the SubStructure Label to Horizontal Plate.
Completed Flat Plate Model.
Step 2. Importing Measurements To display ODS's of the flat plate model, a set of FRFs measured from a real plate structure will be imported into a Data Block file. The Data Block file to be imported (Plate 30 FRFs.UFF) is installed with the (optional) ME'scopeVES Examples during software installation. These FRFs were calculated from force and acceleration data acquired during a roving impact test on a real aluminum plate.
41
Tutorial Volume IA - Basic Operations •
If you have not installed the (optional) Tutorials example files, you should install them before proceeding.
•
Execute File | Import | Data Block in the ME'scopeVES window.
•
Choose Universal File Format (.UFF, .UNV, .ASC) from the Files of Type list in the dialog box.
•
Select the Plate 30 FRFs.UFF file from the My Documents\ME'scopeVES\Tutorials folder, and click on Open.
The Translation Files dialog box will open, as shown below.
Translate Files Dialog Box. •
Click on OK to import the Plate 30 FRFs.UFF file.
The Data Block window will open showing the imported FRFs. Notice on the Title Bar that there are 30 FRFs in the file.
42
•
Execute Display | Magnitude
•
Use the vertical scroll bar on the right of the graphics area to scroll through the FRF measurements.
.
Tutorial #1 - Frequency-Based ODS Animation
Data Block Window Showing Log Magnitude of an FRF.
DOFs for a Roving Impact Test Each of the 30 FRFs in the Data Block is a cross-channel measurement between a pair of DOFs (points & directions) on the real plate structure. Each FRF was measured by impacting the plate with a hammer at a different point in the Z (vertical) direction. The vibration response was measured with an accelerometer fixed at point 1 in the Z direction. This is a very common modal test, and is called a roving impact test. •
Since the accelerometer was fixed at DOF 1Z throughout the test, 1Z is the (fixed) Reference DOF.
•
Since each impact point was different, the roving force input DOFs are the Roving DOFs.
Trace DOFs •
Click & Drag the vertical blue splitter bar to the left in the Data Block window to display the Trace properties spreadsheet.
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Tutorial Volume IA - Basic Operations Plate 30 FRFs Showing DOFs and Units. Trace DOFs of cross-channel measurements such as FRFs have the following form, Trace DOF = Roving DOF : Reference DOF •
The Roving DOF always precedes the colon ":" and the Reference DOF always follows the colon ":".
NOTE: Only cross-channel measurements have both a Roving and a Reference DOF. All other types of measurements have only a Roving DOF. In this example, each Trace has a different Roving DOF (1Z to 30Z) followed by the a single Reference DOF (1Z). Since there is only one reference DOF, this is called a single reference test. Trace Units Notice also that all of the FRFs have the same units, g/lbf. These units indicate that the response (or output) was measured with an accelerometer (in g units), and the excitation force (or input) was measured with a force gauge or load cell (in lbf units).
Animation Equations All shape animation is done by evaluating an Animation equation at each DOF (Point & direction) of a structure model. •
An Animation equation is a weighted summation of measurement numbers (or M#s).
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During animation, each DOF of the structure model is animated by summing together data from each M# in the current Animation Source.
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Any Data Block, Shape Table, or Acquisition window can be an Animation Source.
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A Measured animation equation is created for each DOF where a measurement was made.
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An Interpolated animation equation is created for each DOF where no measurement was made.
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All Fixed DOFs are not be animated.
Current Animation Source During shape animation, data from the current Animation Source is used to display shapes in animation on the structure model.
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•
The current Animation Source is displayed in the Animation Source list on the Structure window Toolbar.
•
Press the Animate | Show Animation Source tool shown below) to display the Data Block window.
next to the Animation Source list (as
Tutorial #1 - Frequency-Based ODS Animation
Animation Source List.
Assigning M#s to Measurement Points & Directions All shape animation is done by evaluating an Animation equation at each DOF (Point & direction) of a structure model. Animation equations are created by assigning the measurements (M#'s) in an Animation Source window to Points & directions (DOFs) of a structure model. To create Animation equations, •
Execute Draw | Animation Equations | Create Measured (Assign M#s) in a Structure window.
This command provides two options for creating animation equations, as shown below
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Match Structure and Source DOFs.
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Graphical Assignment; Select a Point & direction, and assign an M# to it.
There are two requirements for matching each Point & direction of a structure model with the DOF of a measurement (M#), 1. The Point number of each test Point on the model must match the Point number in the Roving DOF of the measurement (M#) taken at that Point. 2. One of the Measurement Axes at the matching Point must coincide with the direction in the DOF of the measurement (M#) taken at that Point. Point Numbering To initiate Point numbering on a model,
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Tutorial Volume IA - Basic Operations •
Execute Draw | Points | Number Points in the Structure window with the model in it.
The Number Points dialog box will open, as shown below, from which you can control the Point numbering process. •
Start with the Point at the origin of the Global axes, and click near each Point on the model to number it, as shown below.
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If you click on the wrong Point, enter the correct Point number into the Next Point Number box in the Number Points dialog, and begin Point numbering again.
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When you have numbered all 30 Points, as shown below, click on Done in the Number Points dialog box
Plate With 30 Points Numbered. Point Label NOTE: Point numbering places the number in the Point Label of each numbered Point. •
Drag the blue splitter bar to the left to display the Label column in the Points spreadsheet.
•
Point numbers are displayed (or hidden) on the model by executing Display | Points | Point Labels
.
Measurement Axes Each Point on a structure model has its own Measurement Axes. The Measurement Axes specify the directions in which measurements were made at each Point. NOTE: Measurement Axes directions are defaulted to coincide with the directions of the Global Axes, which are displayed in the lower right corner of each View in the Structure window. •
Execute Draw | Animation Equations | Equation Editor
.
The Measurement Axes and Animation Equations tabs are now displayed above the Points spreadsheet. •
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The Edit | Select Objects | Click Select
command is also enabled.
Tutorial #1 - Frequency-Based ODS Animation •
Hover the mouse Pointer near a Point to display its Measurement Axes.
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Execute Edit | Select Objects | Select All Points.
•
Execute Edit | Select Objects | Select None
to display the Measurement Axes of all of the
to hide the Measurement Axes on the model.
Plate Structure Showing all Measurement Axes. Notice that the axis Coordinates are Rectangular on the Measurement Axes tab, and that the axis directions coincide with the Global (X, Y, Z) axes in the lower right corner. In this case the Measurement Axes at each Point are oriented with the Z direction pointing in the vertical direction, which also coincides with the direction of measurement at each Point.
Step 3. Creating Measured Animation Equations In this Step, Animation equations will be created so that ODS data from the FRF measurements can be displayed in animation on the plate model. •
Execute Draw | Animation Equations | Create Measured (Assign M#s) in the Structure window.
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With Match Structure and Source DOFs selected In the following dialog box, click on OK.
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Tutorial Volume IA - Basic Operations The following message box will open, confirming that 30 animation equations were created. In other words, all 30 M#s in the Data Block were assigning to 30 DOFs of the structure model.
Examining the Animation Equations In the Data Block window, the first column of the Traces spreadsheet contains the measurement number (M#) of each Trace. When the Animation equations are evaluated during animation, data from each of the 30 Traces (M#s) in the Data Block will be used to animate 30 DOFs of the structure. In this case, each of the 30 Points will be animated in the Z direction using data from each of the 30 Traces in the Data Block. •
Execute Draw | Animation Equations | Equation Editor in the Structure window.
•
Execute Edit | Select Objects | Select All
.
The animation equations are displayed on the Animation Equations tab, as shown below. •
Scroll through the spreadsheet of animation equations to examine them.
Animation Equations Tab.
Step 4. Frequency-Based ODS Animation •
Execute Window | Arrange Windows | For Animation
•
Execute Draw | Animate Shapes
in the ME'scopeVES window.
in the Structure window to initiate the animation.
Animation of ODS data from the Data Block window will begin using Sine Dwell animation.
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Tutorial #1 - Frequency-Based ODS Animation
•
Execute Display | Imaginary
•
Execute Format | Overlaid to overlay all 30 Traces.
in the Data Block to display the Imaginary part of the FRFs.
To animate at a resonance peak and therefore display an approximation of a mode shape, •
Position the mouse pointer inside the graphics area of the Data Block, and click on one of the resonance peaks, as shown below.
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Press the left & right arrow keys on the keyboard to move the cursor in small steps.
Animated ODS at a Resonance Peak. Zoom & Pan the Trace Display •
Position the mouse pointer inside the graphics area of the Data Block window,
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Click on a peak, and spin the mouse wheel to Zoom the display around the peak.
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Hold down the Shift key and click & drag to Pan the Zoomed display.
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Execute Display | mooZ
to display all of Trace data.
Structure Window Commands •
Position the mouse pointer inside the graphics area of the Structure window,
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Spin the mouse wheel to Zoom the display.
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Hold down the Shift key, and click & drag to Pan the display.
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Click & drag to rotate the structure.
NOTE: Click & drag rotation can only be done in the 3D View. •
Click on the up arrow to decrease the amplitude.
to increase the animation amplitude, and on the down arrow
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Tutorial Volume IA - Basic Operations •
Execute Animate | Deformation | Undeformed together with the deformed structure.
to display the un-deformed structure
Changing Surface Colors
Execute Animate | Draw Structure
Execute Edit | Object List | Surface Quads.
Execute Edit | Select Objects | Select None
Hold down the Ctrl key, hover the mouse pointer over the surfaces on the model, and click to select two rows of Surface Quads, as shown below.
to stop the animation.
.
Selected Surface Quads.
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Click on the Color column heading in the Objects spreadsheet.
Choose a single color for the selected Quad Objects, and click on OK.
Right click on the Objects spreadsheet, and execute Invert Selection from the menu.
Click on the Color column heading again, and choose a different color for the selected Surface Quads.
Tutorial #2 - Drawing Structure Models Requirements for Animation The following steps are required in order to display shapes in animation on a structure model, 1. Create a Structure Model •
Draw the model in a Structure window.
•
Or import a structure model.
2. Import or Acquire Measurements •
Import sampled time or frequency data into a Data Block, or shape data into a Shape Table.
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Or acquire time or frequency data directly from an acquisition front end using an Acquisition window.
3. Create Animation Equations •
Execute Draw | Animation Equations | Create Measured in the Structure window.
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Or execute Tools | Create Animation Equations in an Animation Source window (Data Block, Shape Table or Acquisition window).
4. Start Animation •
Execute Draw | Animate Shapes in the Structure window.
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Or execute Tools | Animate Shapes in the Animation Source window.
Types of Drawing Objects Structure models are created using the following Drawing Objects; •
Points
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Lines (Lines are defined between 2 Points)
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Surfaces (Triangles are defined between 3 Points, Surface Quads are defined between 4 Points.)
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Substructures •
A Substructure is a collection of Points, Lines & Surfaces.
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Substructures can be manipulated just like Points, Lines & Surfaces.
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Complex structure models are more easily created by assembling together several Substructures.
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Multiple Substructures can reference the same Points, Lines & Surfaces.
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Tutorial Volume IA - Basic Operations
Drawing Objects.
Point Coordinate Units NOTE: Length units are not required in order to draw a structure model. Units can be chosen at any time, even after the model has been created. To select Length units for the Point coordinates; •
Execute File | Structure Options in the Structure window.
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On the Units tab, choose the desired Length units, and click on OK.
Types of Models All structure models consist of Points, Lines & Surfaces. Structure models are given several different names; Wire frame or stick model •
Consists of Points & Lines.
Surface model •
A stick mode with Surfaces.
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Lines are optional.
Texture or photo realistic model •
A surface model with Surface textures.
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Lines are optional.
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A photo realistic model has digital photos as Surface textures.
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A photo realistic model is imported from a WaveFront (.OBJ) file.
Example 1. Creating a Cone SubStructure
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Tutorial #2 - Drawing Structure Models A cone structure shown below will be created by starting with a cylinder SubStructure obtained from the Drawing Assistant.
Cone SubStructure. •
Execute Project | New to open a new Project file.
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Execute File | New | Structure in the ME'scopeVES window to open a new (empty) Structure window.
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Execute Draw | Drawing Assistant
in the Structure window.
The Drawing Assistant tabs are displayed above the SubStructures spreadsheet on the right side of the window. •
On the SubStructure tab, Double click on the Editable Cylinder SubStructure from the browser.
•
On the Dimensions tab, enter 20 Points into the spreadsheet as shown below.
Cylinder With 20 Points on Each End.
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Tutorial Volume IA - Basic Operations •
Execute Edit | Object List | Points to close the Drawing Assistant and display the Points spreadsheet.
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Execute Edit | Select Objects | Selection Box.
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Draw a Selection Box to enclose the Points on one end of the cylinder, as shown below.
Points Selection Box. •
Execute Edit | Resize Objects.
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Move the mouse pointer into the graphics area.
Notice that the mouse cursor is changed to the re-size cursor. •
Click & drag the mouse cursor from the upper right corner toward the lower left corner of the graphics area.
Notice how the cylinder changes into a cone. •
If you make a mistake, execute Edit | Undo and repeat the above steps.
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Execute Edit | Object List | SubStructures to display the SubStructures spreadsheet.
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Press the Select SubStructures button on the SubStructures spreadsheet.
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Execute Draw | Mesh Selected Objects | Mesh Longest Edge.
The longest edges of the Surfaces on the cone are now divided in half.
Example 2. Building the Jim Beam with Plate SubStructures The Jim Beam structure shown below will be built using three SubStructures from the Drawing Assistant.
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Tutorial #2 - Drawing Structure Models
3-Plate Beam Structure. •
Execute Project | New to open a new Project file.
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Execute File | New | Structure in the ME'scopeVES window to open a new (empty) Structure window.
•
Execute Draw | Drawing Assistant
in the Structure window.
The Drawing Assistant tabs will be displayed above the SubStructures spreadsheet on the right side of the window. Bottom Plate A Bottom Plate SubStructure will be created as a grid of Points spaced 1 unit apart, with 3 Points in the width direction and 5 Points in the height direction. On the SubStructure tab •
Double click on the Editable Plate SubStructure from the browser to add a vertical plate SubStructure to the window.
On the Dimensions tab •
Enter Width = 6 and Points = 3 below it.
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Enter Height = 12 and Points = 5 below it.
On the Position tab •
In the Rotate area, enter 45 into the Degrees box.
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Click on the Y Up Arrow twice to rotate the plate into a horizontal position, as shown below.
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Double click on the Label column header in the SubStructure spreadsheet (lower right), and enter "Bottom Plate" into the dialog box.
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Tutorial Volume IA - Basic Operations
Drawing Assistant Showing the Bottom Plate. Top Plate The Top Plate will be created by making a copy of the Bottom Plate. •
Execute Edit | Copy Objects to File.
Since the Bottom Plate is still selected in the SubStructures spreadsheet, it will be copied. •
Select STR: Structure_1 in the dialog box that opens, and press the Add To button.
Notice that there are now two SubStructures in the SubStructures spreadsheet.
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•
Select only the second SubStructure in the SubStructures spreadsheet.
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Click on the Z Up Arrow 4 times in the Local Origin area on the Position tab.
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Enter 0.75 into the Increment box, and click on the Z Up Arrow one more time.
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Double click on the Label column header in the SubStructure spreadsheet, and enter "Top Plate" into the dialog box.
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Double click on the Color column header, and select Red as the Surface color.
Tutorial #2 - Drawing Structure Models
Drawing Assistant Showing Top and Bottom Plates. Back Plate The Back Plate SubStructure will be created as a grid of Points spaced 1 unit apart, with 3 Points in the width direction and 3 Points in the height direction. On the SubStructure tab •
Double click on the Editable Plate SubStructure again to add another plate to the drawing.
On the Dimensions tab •
Enter Width = 6 and Points = 3 below it.
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Enter Height = 4.75 and Points = 3 below it.
In the SubStructure spreadsheet •
Double click on the Label column header, and enter "Back Plate" into the dialog box.
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Double click on the Color column header, and select Blue as the Surface color.
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Tutorial Volume IA - Basic Operations
Completed 3-Plate Structure.
Quad View and Active View A structure model can be displayed in one of four Views, or all four Views together in a Quad View. •
Double click anywhere on a Single View to display the Quad View.
•
Double click anywhere on one of the Views in the Quad View to display only that View.
Active View NOTE: One of the four Views is always active in the Structure window. •
The active View is indicated by the yellow box in the Display | View list
.
If the upper right quadrant is yellow, the 3D View is active. •
Click anywhere on a View to make it active.
Zoom & Pan To Zoom the structure model in a View, •
Click in the View to make it active, and spin the mouse wheel.
To Pan the structure model in a View, •
Hold down the Shift key, and click & drag the mouse in the View.
To Re-center the structure model in a View, •
Click in the View to make it active, and execute Display | mooZ
NOTE: The Display | View Control command can also be used to Zoom & Pan the active View.
Example 3. Creating a Plate with Points, Lines & Surfaces
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Tutorial #2 - Drawing Structure Models The plate model shown below will be created using four Points, four Lines, and two Surface Triangles. •
Execute Project | New to open a new Project file.
•
Execute File | New | Structure in the ME'scopeVES window to open a new (empty) Structure window.
Plate Model with 4 Points, 4 Lines, and 2 Surface Triangles. Global Axis Lines •
Execute File | Structure Options to open the Options box.
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On the Labels tab, check the Axis Lines box and click on OK.
Larger Point Size •
Execute File | Structure Options to open the Options box.
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On the Display tab, change the Point Size to 5 and click on OK.
Re-Arranging Spreadsheet Columns The Points spreadsheet columns can be re-arranged so that it is easier to work with the Point Coordinates. •
Click & drag the X coord. column heading in the Points spreadsheet to position it next to the Hide column, as shown below.
•
Click & drag the Y coord. column heading, then the Z coord. column heading into position, as shown below
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Tutorial Volume IA - Basic Operations
Structure window Ready for Drawing.
Adding Points •
Double click in the 3D View to display the Quad View.
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Choose Points
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Execute Edit | Add Objects
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Move the mouse pointer into the X View, and click to add the first corner Point near the origin, as shown below.
in the Edit | Object Type list. to enable the Add Points operation.
When a new Point is added to the drawing, it is displayed as a selected Point in all Views, and a new row is added to the Points spreadsheet on the right of the vertical blue splitter bar. WARNING: When the Add Points operation is enabled, each time you click on a View, a new Point will be added to the model.
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•
Move the mouse pointer to the next approximate corner of the square, and click to add the next corner Point.
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Add the last two corner Points of the square to form an approximate square, as shown below.
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Execute Edit | Add Objects
again to terminate the Add Points operation.
Tutorial #2 - Drawing Structure Models
Structure Window Showing Four Corner Points.
Editing Point Coordinates The coordinates of the four previously added corner Points can be edited so that they form a perfect square. The coordinates of multiple Points can be changed by first selecting them and then editing their global X, Y, or Z coordinates. •
Double click on the X View to display it alone.
To align the two Points on the left side of the square, •
Un-select all Points.
•
Hold down the Ctrl key, and click near the upper left corner Point to select it, then click near the lower left corner Point to select it, as shown below.
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Double click on the Y coord. column heading in the Points spreadsheet to open the Y Coordinate editing box.
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Enter "0" into the dialog box, and click on OK.
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Tutorial Volume IA - Basic Operations
Y-Coordinate Editing Box. To align the two Points on the right side of the square, •
Un-select all Points.
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Hold down the Ctrl key, and click near the upper right corner Point to select it, then click near the lower right corner Point to select it.
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Double click on the Y coord. column heading to open the Y Coordinate column editing box.
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Enter a "1" into the dialog box, and click on OK.
To align the two Points on the bottom of the square, •
Un-select all Points.
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Hold down the Ctrl key, and click near the lower left corner point to select it, then click near the lower right corner Point to select it.
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Double click on the Z coord. column heading in the Points spreadsheet to open the Z Coordinate column editing box.
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Enter a "0" into the dialog box, and click on OK.
finally, to align the two Points on the top of the square,
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•
Un-select all Points.
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Hold down the Ctrl key, and click near the upper left corner Point to select it, then click near the upper right corner Points to select it.
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Double click on the Z coord. column heading in the Points spreadsheet to open the Z Coordinate column editing box.
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Enter a "1" into the dialog box, and click on OK.
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Execute Display | Re-Center All Views to make the model visible in all Views.
Tutorial #2 - Drawing Structure Models
Four Points Aligned in a Square.
Adding Lines to the Model Each Line is defined between 2 Points. Adding Lines between Points turns the drawing into a stick model. •
Choose Lines
•
Execute Edit | Add Objects
•
Click near a corner Point to select it.
•
Click near an adjacent corner Point to select it.
in the Edit | Object Type list. to enable the Add Lines operation.
Notice that after you selected the second Point, a new selected Line was added between the two Points on the drawing, and a new row was added to the Lines spreadsheet. WARNING: When the Add Lines operation is enabled, a new Line will be added to the model each time you click near two different Points in succession. •
Repeat the above steps to add the other three Lines needed to define the square, as shown below.
•
Execute Edit | Add Objects again to terminate the Add Lines operation.
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Tutorial Volume IA - Basic Operations
Plate After Adding Four Lines.
Adding Surfaces to the Model A Surface Triangle is defined between 3 Points. NOTE: Surfaces are required in order to display shape Contour Colors and Node Lines during animation. •
Choose Surface Triangles
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Execute Edit | Add Objects
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Click near a corner Point to select it.
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Click near an adjacent corner Point to select it.
•
Click near another corner Point to select it.
in the Edit | Object Type List. to enable the Add Surfaces operation.
After you have selected three Points, a new selected Surface Triangle is displayed between the Points, and a new row is added to the Surface Triangles spreadsheet on the right of the vertical blue splitter bar. WARNING: When the Add Surfaces operation is enabled, a new Surface Triangle will be added to the model each time you click near three different Points in succession.
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•
Repeat the above steps to add the second Surface Triangle that defines the other half of the surface, as shown below.
•
Execute Edit | Add Objects again to terminate the Add Surfaces operation.
Tutorial #2 - Drawing Structure Models
Plate With 2 Surface Triangles.
Creating a SubStructure The square plate model (consisting of 4 Points, 4 Lines, and 2 Surface Triangles) can be defined as a SubStructure. NOTE: SubStructures only reference drawing Objects. Objects referenced by SubStructures still exist as unique Objects in the Structure file. Multiple SubStructures can reference the same Objects. •
Choose Points
•
Execute Edit | Select Objects | Select All
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Execute Draw | Add Objects to SubStructure.
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Press the New SubStructure button in the dialog box that opens. •
in the Edit | Object Type List. to select all Points.
Click on OK to create a new SubStructure.
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The selected Points, plus the Lines & Surfaces that use the Points, are all referenced by the new SubStructure.
•
is chosen from the Edit | Object Type List, and that the Notice also that SubStructures SubStructure spreadsheet contains the new SubStructure.
SubStructure Library Any model in a Structure window can be added to the SubStructure Library and used for building other models. All of the SubStructures in the SubStructure Library are displayed in the SubStructure browser when the Drawing Assistant tabs are displayed. •
Execute File | Save In Library to add the square plate Structure to the SubStructure Library,
Example 4. Extruding a 2D SubStructure Many 3D models can be built by extruding or revolving a 2D profile or cross section of a structure. In this example, a 2D cross section of an I-beam will be extruded to create a 3D I-beam model.
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Tutorial Volume IA - Basic Operations •
Execute Project | New to open a new Project file.
•
Execute File | New | Structure in the ME'scopeVES window to open a new (empty) Structure window.
•
Execute Draw | Drawing Assistant Assistant tabs.
•
On the SubStructure tab,
•
•
in the Structure window to display the Drawing
•
Double click on the Editable Plate SubStructure from the browser.
•
A vertical plate SubStructure will be displayed, as shown below.
On the Dimensions tab, •
Enter Width = 4 and Points = 4 below it.
•
Enter Height = 6 and Points = 6 below it.
On the Position tab, •
Click on the Global button to center the SubStructure about the Global origin.
Editable Plate SubStructure. •
Choose Points
•
Execute Edit | Select Objects | Select None
•
Hold down the Ctrl key, and click near the two mid-Points on each side to select them, as shown below.
•
Execute Edit | Delete Selected Objects to delete the selected Points.
in the Edit | Objects list. to un-select all Points.
A dialog will open asking if you want to also delete the other Objects using the Points. •
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Click on Yes to also delete the Lines & Surfaces connected to the selected Points.
Tutorial #2 - Drawing Structure Models
Plate SubStructure Showing Selected Points to be Deleted.
Plate SubStructure With Deleted Points, Lines, and Surfaces. The (vertical) web of the beam will be narrowed so that it is 0.5 length units wide. •
Execute Edit | Select Objects | Selection Box on the left side on the web, as shown below.
•
Double click on the Y coord. column heading in the Points spreadsheet. •
•
and draw a selection box around the Points
Enter "-0.25" into the dialog box that opens, and click on OK.
Repeat the steps above, but this time select the Points on the right side of the web, and change their Y coord. to "0.25".
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Tutorial Volume IA - Basic Operations
Plate SubStructure Showing Selected Points on the Web.
Plate SubStructure Showing 0.5 Units Wide Web. The Structure should look like the one shown in the figure above. Next, the top & bottom (horizontal) flanges will also be narrowed to 0.5 length units. •
Select the bottom row of Points on the top flange, and change their Z coord. to "2.5".
•
Select the top row of Points on the bottom flange, and change their Z coord. to "-2.5".
The cross section should now look like the one shown below.
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Tutorial #2 - Drawing Structure Models
Plate SubStructure Showing Narrow Web and Flanges. Extruding the Cross Section •
Execute Draw | Drawing Assistant
•
Select the Plate SubStructure.
•
On the Extrude tab,
to display the Drawing Assistant tabs again.
Select X in the Extrude Axis section.
Enter Length = 50, and Points = 10.
Click on the Extrude button to create the I-beam, as shown below
I-Beam SubStructure.
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Tutorial Volume IA - Basic Operations Example 5. Tracing Profile from a Photograph A 2D profile can be traced from a digital photograph by placing the photograph in the background of one of the 2D Views in the Structure window. In this example, the profile of a car will be created by tracing it from a side view photograph of the car. Following that, wheels will be added to the profile using the Drawing Assistant. •
Execute Project | New and create a new Project file.
•
Execute File | New | Structure in the ME'scopeVES window to open a new (empty) Structure window.
•
Execute File | Options in the Structure window to open the Structure Options box.
On the Display tab,
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•
Choose Y View, as shown below.
•
Click on the Import button, and open vette05.JPG from the My Documents\ME'scopeVES\Tutorials folder.
•
Check Disable Auto Scaling.
Tutorial #2 - Drawing Structure Models
Structure Window Showing Corvette Photo as Background. •
Display the Y View in the Structure window.
A car profile should be in the background of the Y View, as shown above. Tracing a Car Profile •
Maximize the Structure window, and drag the spreadsheet splitter bar to the right.
•
Choose Points
•
Execute Edit | Add Object
•
Move the mouse pointer into the Y View, and click on the edge of the red body to add a Point.
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Continue clicking along the edge of the red body to add as many profile Points as desired.
•
When you have completed the profile, execute Edit | Add Object Add Points operation.
in the Edit | Object List. to enable the Add Points operation.
again to terminate the
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Tutorial Volume IA - Basic Operations
Y View Showing Points Added to Define the Car Profile. •
Choose Lines
•
Execute Edit | Add Objects
•
Click near a Profile Point to select it.
•
Click near an adjacent Point to add a new Line between the two Points.
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Repeat the two steps above until all desired Lines are added to the car Profile.
from the Edit | Object List. to enable the Add Lines operation.
Completed Car Body Profile.
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•
To remove the photograph from the Y View, execute File | Options to open the Structure Options box.
•
On the Display tab, select the Y View, and press the Remove button.
Tutorial #2 - Drawing Structure Models •
Un-check Disable Auto Scaling, and click on OK.
Adding Wheels •
Execute File | New | Structure in the ME'scopeVES window to open a new Structure window.
•
Execute Draw | Drawing Assistant to display the Drawing Assistant tabs.
On the SubStructure tab, •
Double click on the Editable Circle.
On the Position tab, •
Rotate the SubStructure about the Z-axis so that it is "facing" the Y-axis.
On the Dimensions tab, •
Enter the parameters shown in the figure below.
Wheel SubStructure. •
In the Structure window containing the car profile, execute Edit | Paste Objects from File.
•
In the dialog box that opens, choose the Structure window with the wheel in it, and click on Paste.
•
Execute Edit | Drag Selected Objects, and drag the wheel into the front wheel opening in the profile.
•
Repeat the steps above to Paste another copy of the Editable Circle, and drag it into the rear wheel opening, as shown below.
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Tutorial Volume IA - Basic Operations
Car Profile With Wheels.
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Tutorial #3 - Importing Measurement Data Requirements for Animation The following steps are required in order to display shapes in animation on a structure model, 1. Create a Structure Model •
Draw the model in a Structure window.
•
Or import a structure model.
2. Import or Acquire Measurements •
Import sampled time or frequency data into a Data Block, or shape data into a Shape Table.
•
Or acquire time or frequency data directly from an acquisition front end using an Acquisition window.
3. Create Animation Equations •
Execute Draw | Animation Equations | Create Measured in the Structure window.
•
Or execute Tools | Create Animation Equations in an Animation Source window (Data Block, Shape Table or Acquisition window).
4. Start Animation •
Execute Draw | Animate Shapes in the Structure window.
•
Or execute Tools | Animate Shapes in the Animation Source window.
Measurement Types Vibration data is usually acquired by attaching one or more vibration transducers to the surface of a machine or structure. •
Acceleration response is typically measured using an accelerometer.
•
Velocity is measured using a Laser vibrometer, and machine shaft displacement is measured using a Proximity probe.
While the machine or structure is vibrating, sampled time domain data from the transducers is acquired using a multi-channel data acquisition system, FFT analyzer, data recorder, or portable data collector. Further signal processing is then performed on the acquired time domain signals, and special types of measurement functions are calculated. In order to display shapes, a set of measurements must be acquired at all DOFs (points & directions) where shape values are desired. Typical sets of measurements used to obtain ODS's and mode shapes are; •
Multi-channel time domain responses: they must be simultaneously acquired.
•
FRFs: An FRF is the Fourier spectrum of a response divided by the Fourier spectrum of the force that caused the response.
•
Transmissibility's: A Transmissibility is the Fourier Spectrum of a response divided by the Fourier Spectrum of a (fixed) reference response.
•
Cross spectra: A Cross spectrum is the Fourier Spectrum of a response multiplied by the complex conjugate of the Fourier Spectrum of a fixed reference response.
•
ODS FRFs: An ODS FRF is the Auto Spectrum of a response combined with the phase between the response and a fixed reference response.
Time Domain Measurements
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Tutorial Volume IA - Basic Operations In order to display ODS's or mode shapes from a set of time domain response measurements, they must all be acquired so that each measurement represents a shape component of the structure at the same moment in time. Another way of saying this is that all responses contain the correct magnitude & phase relative to one another. •
If all of the channels of time domain data are simultaneously acquired, the responses contain the correct magnitude & phase relative to one another.
•
Simultaneous acquisition requires a separate transducer for each measured DOF, and a large, multi-channel data acquisition system.
•
Since this is typically too expensive, data is usually acquired a few channels at a time in separate Measurement Sets.
Repeatable Acquisition •
During repeatable acquisition, approximately the same time waveform is obtained in the sampling window of the analyzer or acquisition system, regardless of when it is acquired.
•
A trigger is usually required to capture a repeatable event in the sampling window.
•
Repeatable acquisition will yield the same Fourier spectrum of successively sampled time waveforms, as shown below.
Acquisition of a Repeatable Event.
Frequency Domain Measurements An advantage of frequency domain measurements is that they don't require simultaneous acquisition of all channels of data. •
FRFs, Transmissibility’s, Cross spectra and ODS FRFs are cross channel measurements that do not require simultaneous acquisition of all channels.
•
In order to obtain ODS's or mode shapes from a set of these measurements, the structure must remain in a steady state during the acquisition process.
Steady State Acquisition A steady state (or stationary) acquisition is achieved when the Auto spectrum of an acquired signal does not change from one measurement to another. An Auto spectrum is the Fourier Spectrum of a signal multiplied by its own complex conjugate.
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Tutorial #3 - Importing Measurement Data
Steady State Acquisition. Cross-Channel Measurements •
FRFs, Transmissibility’s, Cross spectra and ODS FRFs are all cross-channel measurements. •
These measurements are calculated between two signals that have been simultaneously acquired on two different acquisition channels.
•
An FRF requires that a response and its corresponding excitation force be simultaneously acquired.
•
A Transmissibility, Cross spectrum or ODS FRF requires that a roving response and a (fixed) reference response be simultaneously acquired.
FRF Measurements •
FRFs are ideal measurements for identifying experimental mode shapes because each peak in an FRF is evidence of at least one mode.
•
A set of FRFs between a single excitation point and multiple response points, or between a single response point and multiple excitation points, is used to identify the mode shapes of a structure.
Operating Data •
When excitation forces cannot be measured, then FRFs cannot be calculated.
•
Transmissibility's, Cross spectra, and ODS FRFs can be calculated from Operating (or Output Only) data. •
•
•
Operating mode shapes are extracted from these measurements.
A Transmissibility is calculated in the same way as an FRF, but the unmeasured excitation force is replaced by a (fixed) reference response. •
At or near a resonant frequency, the values of a set of Transmissibility’s is an approximation of the operating mode shape.
•
However, each Transmissibility has a ”flat spot” instead of a peak at each resonant frequency.
•
At least one Auto or Cross spectrum is needed to locate resonance peaks in order to obtain operating mode shapes from a set of Transmissibility's
A Cross spectrum or an ODS FRF has peaks at resonant frequencies.
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Tutorial Volume IA - Basic Operations •
A set of Cross spectra or ODS FRFs between multiple roving response DOFs and a single reference response DOF can be used to display ODS’s.
•
With special windowing, these measurements can be curve fit with FRF-based curve fitting methods to obtain operating mode shapes.
Importing a Data Block Time or frequency domain measurements can be imported into ME'scopeVES from one or more third party disk data files. After the data has been imported, it can be saved in a Data Block (BLK) file in the current Project, and need not be imported again. •
Execute the File | Project | New command to create a new Project file.
•
Execute File | Import | Data Block in the ME'scopeVES window.
•
Navigate to the folder My Documents / ME'scopeVES / Brake Rotor Data.
•
Choose Universal File Format in the Files of Type list displayed adjacent to the File Name text box.
All of the files of the type you chose (UFF) will be listed in the dialog box. Selecting Multiple Files Some analyzers and data acquisition systems save only one measurement per disk file. Multiple files can be imported together and put into one Data Block. •
Select the first file in the list by clicking on its Name in the list box.
•
Scroll to the last file name in the list box.
•
Hold down the Shift key and click on the last file to select (highlight) all files in the list box, as shown below.
•
Click on the Open button.
Windows Open File Dialog Box Showing Multiple Files Selected. Translate Files Dialog Box
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Tutorial #3 - Importing Measurement Data Next, the Translate Files dialog box will open displaying properties of each imported measurement (called a Trace) in a spreadsheet. You can edit Trace properties in this spreadsheet if required. NOTE: All of the Trace properties in the Translate Files spreadsheet can also be edited in the Traces spreadsheet in the Data Block window after the Data Block has been imported. •
Press buttons in the Select Trace column to select the Traces to be imported.
In none is selected, then all Traces will be imported. •
Press the OK button to import the Data Block of Traces.
A new Data Block window will open showing the imported data.
Translate Files Dialog Box.
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Tutorial Volume IA - Basic Operations
Data Block Displaying Imported FRFs.
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Tutorial #4 - Time-Based ODS Animation Requirements for Animation The following steps are required in order to display shapes in animation on a structure model, 1. Create a Structure Model •
Draw the model in a Structure window.
•
Or import a structure model.
2. Import or Acquire Measurements •
Import sampled time or frequency data into a Data Block, or shape data into a Shape Table.
•
Or acquire time or frequency data directly from an acquisition front end using an Acquisition window.
3. Create Animation Equations •
Execute Draw | Animation Equations | Create Measured in the Structure window.
•
Or execute Tools | Create Animation Equations in an Animation Source window (Data Block, Shape Table or Acquisition window).
4. Start Animation •
Execute Draw | Animate Shapes in the Structure window.
•
Or execute Tools | Animate Shapes in the Animation Source window.
Animation Equations During shape animation in a Structure window, the structure model is animated by evaluating an Animation equation for each direction at each Point on the model. •
An Animation equation is a weighted summation of measurements (or M#s).
•
If the current Animation source has an M# that matches the M# in an Animation equation, data from that M# is used in the equation to animate a DOF of the model.
•
Each Trace in a Data Block or Acquisition window has a unique M#.
•
Each shape DOF in a Shape Table also has a unique M#.
Measured, Interpolated, and Fixed DOFs Each DOF (Point & direction) of a structure model can have a Measured animation equation, an Interpolated animation equation, no equation, or it can be a Fixed DOF. •
•
Measured equation •
A Measured equation is created when each M# in an Animation source (Data Block, Shape Table or Acquisition window) is assigned to a DOF of the structure model.
•
Measured equations are created by executing either Draw | Animation Equations | Create Measured in a Structure window, or Tools | Create Animation Equations in an Animation source window.
Interpolated equation •
An Interpolated equation is created for each un-measured DOF using nearby Measured equations, and also taking into account nearby Fixed DOFs.
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Tutorial Volume IA - Basic Operations • •
Interpolated equations are created by executing Draw | Animation Equations | Create Interpolated in a Structure window.
Fixed DOF •
A Fixed DOF has no motion during animation.
•
Fixed DOFs are created on a model by executing Draw | Animation Equations | Fix DOFs in its Structure window.
Creating Animation Equations The Animation Equations tab displays the Animation equations for all (or selected) Points on the model. •
Scroll though the Animation equations in the spreadsheet on the tab.
Point Labels use the notation: spreadsheet row number [ user defined label ] Notice that the X & Y directions at each Point are set to Interpolated, and there is no Animation equation for them. •
DOF 1[1] Z is animated using the equation +1.0(M#2).
•
DOF 2[2] Z is animated using the equation +1.0(M#1).
•
DOF 3[3] Z is animated using the equation +1.0(M#4).
•
DOF 4[4] Z is animated using the equation +1.0(M#3).
Animation Equations Tab. Current Animation Source The current Animation Source is listed in the Animation Source list on the Toolbar. •
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The Animation Source list contains the names of all open Data Blocks, Shape Tables, and Acquisition windows.
Tutorial #4 - Time-Based ODS Animation Any of the files in this list can be chosen as the current Animation Source. In this example, the current Animation Source is BLK: CAR. Creating Measured Animation Equations Measured animation equations are created by assigning M#s in an Animation Source window to DOFs of a model in a Structure window. Measured animation equations can be created either by executing a command in the Structure window or in the Animation Source window. •
Execute Draw | Animation Equations | Create Measured in a Structure window.
•
Or execute Tools | Create Animation Equations in a Data Block, Shape Table or Acquisition window.
There are two methods for creating Measured animation equations, •
Match structure Point numbers & Measurement Axis directions (DOFs) with DOFs of the M#s in the current Animation Source.
•
Graphically select a Measurement Axis at each Point on the structure model and assign a M# from the current Animation Source to it.
Matching Structure and Source DOFs Before creating Measured equations by matching Structure DOFs and M# DOFs, the structure model and current Animation Source must be setup as follows; 1. Each M# In the current Animation Source must have a DOF containing the Point number & direction where the measurement was made on the test article. 2. The Label of each test Point on the structure model must be numbered (1, 2, 3, etc.) to match the number in it corresponding M# DOF in the current Animation Source. 3. The Measurement Axes at each test Point must be the same type (Rectangular (X, Y, Z), Cylindrical (R, T, Z) , Spherical (R, T, P), or Machine (A, H, V), as the directions of the M# DOFs in the current Animation Source, and the Measurement Axes must also coincide with the actual directions of measurement.
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Tutorial Volume IA - Basic Operations Data Block Showing Trace (M#) DOFs. •
Drag the vertical blue splitter bar to the left in the BLK: CAR window to display the DOFs column in the Traces spreadsheet, as shown below.
•
Execute Display | Points | Point Labels the four test Points on the model.
in the Structure window to check the numbering of
Notice that the four corner Points on the Structure have the Point numbers (1 to 4) which correspond to the point numbers in the Trace DOFs.
Car Model Showing Point Labels. •
Execute Draw | Animation Equations | Delete Equations in the Structure window.
•
Click on OK and Yes in the dialog boxes that follow to clear all of the Animation equations from the structure model.
•
Execute Draw | Animate Shapes
.
Since there are no Animation equations on the model, Draw | Animation Equations | Create Measured is automatically executed.
•
Make sure that Match Structure and Source DOFs is selected.
•
Click on OK in the dialog box that opens.
Animation of the four corner Points using the data from BLK: CAR will begin.
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Tutorial #4 - Time-Based ODS Animation Displaying Measured DOFs Another way to verify the Measured equations is to display the Measured DOFs on the model. •
Execute Animate | Draw Structure
•
Execute Display | Points | Show Measured DOFs.
to stop the animation.
Notice that one Point is selected and that its Measured DOF is displayed on the structure model using a red arrow, and its equation in contained in a balloon near it. •
Hold down the Ctrl key and click near the other three corner Points to display their Measured DOFs.
Structure Model Showing Measured DOFs.
Creating Interpolated Equations So far in this Tutorial, only the Points & directions with Measured animation equations are animated. When Interpolated animation equations are created and Interpolation is enabled, all Points & directions will be animated. •
Execute Display | Points | Measured DOFs again to turn OFF the display of the Measured DOFs.
•
Execute Draw | Animation Equations | Create Interpolated.
The following dialog box will open, allowing you to choose directions for creating Interpolated equations. •
Click on OK to create equations in all directions.
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Tutorial Volume IA - Basic Operations
The following dialog box will open allowing you to specify the maximum number of geometrically close Measured and Fixed DOFs that will be used to create each Interpolated equation. •
Enter "4" and click on OK.
After the Interpolated equations have been created, the dialog box above will open, The CAR model has 57 Points. Four Points already have Measured equations in the Z direction, Interpolated equations were created for the remaining 53 Points using the M#s from the four nearest Measured Points, which are the four corners. To examine the Interpolated equations,
86
•
Execute Draw | Animation Equations | Equation Editor.
•
Select an un-measured (Interpolated) Point.
•
Click on the Animation Equations tab to display its Interpolated equation.
Tutorial #4 - Time-Based ODS Animation
Interpolation Equation for an Un-Measured Point. To display the Interpolated DOFs, •
Execute Display | Points | Interpolated DOFs.
•
Click near an un-measured Point to display its animation equation.
Deformed and Un-deformed Structure •
Execute Draw | Animate Shapes
•
Execute Animate | Deformations | Undeformed together with the deformed model, as shown below.
. to display the un-deformed model
Animation Showing Deformed & Un-deformed Structure.
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Tutorial Volume IA - Basic Operations Animation From a Data Block When a Data Block is chosen as the current Animation Source, shapes are displayed on a structure model by using Trace (M#) data from the cursor position. •
If the Line cursor is displayed, the Trace (M#) value at the cursor position is used as a component of the shape.
•
If the Peak cursor is displayed, the Trace (M#) value at the peak location in the band is used as a component of the shape.
•
If the Band cursor is displayed, the RMS of the Trace data in the cursor band is used as a component of the shape.
Animation Methods •
Execute each of commands in the Animate | Method list different types of animation.
to observe the three
Sweep Animation During sweep animation, the Data Block cursor is swept through the Traces from left to right. When the cursor reaches the right end of the Traces, it starts over at the left end. •
Drag the cursor in the Data Block window to begin sweep animation from any position.
•
Execute Display | Zoom in the Data Block window, and draw a Zoom box to confine the sweep animation to the visible samples of Trace data.
Sine or Stationary Dwell During sine dwell or stationary dwell animation, the cursor position is fixed and shape data is displayed from the current cursor position. •
During sine dwell animation, each shape component is multiplied by sine wave values that range between –1 & +1.
•
During stationary dwell, the shape values are displayed on the structure without any sinusoidal modulation.
•
Click & drag the cursor in the Data Block window to display the shape at the cursor position.
Animation Speed •
Click on the turtle of the rabbit animation speed.
on the Toolbar to decrease or increase the
Data Block Sweep Speed During sweep animation, the animation speed is controlled by how many samples of Trace data are skipped or interpolated between.
88
•
For a speed of 1, every sample of Trace data is displayed during a sweep.
•
For a speed of 2, every other sample is displayed, for a speed of 3, every third sample is displayed, and so on.
•
For a speed less than 1, shape values are calculated using linear interpolation between adjacent samples of Trace data.
Tutorial #4 - Time-Based ODS Animation •
For a speed of 0.5, one interpolated value is calculated half way between adjacent samples, for a speed of 0.33, two interpolated values are calculated between adjacent samples, and so on.
Sine Dwell Speeds During sine dwell animation, the animation speed is controlled by using a different number of sine values per cycle of animation. •
For a speed of 4, four sine values per cycle is used.
•
For a speed of (N>4), N sine values per cycle are used.
Animation Amplitude The amplitude of shape animation is influenced by the type of shape scaling you choose (see Shape Scaling), and by using the Animate | Amplitude commands •
Execute Animate | Amplitude | Increase Amplitude Amplitude
•
. or Animate | Amplitude | Decrease
to change the animation amplitude.
Execute Animate | Amplitude | Amplitude that opens.
to enter an amplitude value in the dialog box
The current animation amplitude is displayed in the Settings box, which is displayed in each View. •
Execute File | Options in the Structure window.
•
On the Labels tab, check Settings to display the Settings box in each View during animation.
Shape Scaling During animation, shapes are scaled in one of three different ways. •
Execute Animate | Scale Shapes | Auto Scale to enable Auto scaling.
•
Or execute Animate | Scale Shapes | Relative Scale to enable Relative scaling.
•
Or execute Animate | Scale Shapes | Fixed Scale to enable Fixed scaling.
Auto Scaling •
When Auto scaling is enabled, each shape component is divided by the maximum component of the shape.
•
When dwell animation is initiated, Auto Scaling is automatically enabled, unless Fixed Scaling is enabled.
Relative Scaling •
When Relative scaling is enabled, each shape is divided by the maximum shape component of all data in the current Animation Source.
•
When sweep animation is initiated, Relative scaling is automatically enabled, unless Fixed scaling is enabled.
Fixed Scaling •
When Fixed scaling is enabled, each shape is scaled using a user-defined fixed scale factor.
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Tutorial Volume IA - Basic Operations Assume that an animating structure model has the following values; The largest structure coordinate = 100 Length Units. The Animation Amplitude = 1. The largest shape component (M# value) = 10. To fix the maximum amplitude of an animated shape so that it is 20% of the largest structure coordinate. Maximum Amplitude = 0.20 x 100 = (Fixed Scale Factor) x (1) x (10) Therefore: Fixed Scale Factor = 20/10 = 2.
Deformation, Arrows, and Contours Shapes can be displayed in animation using one of the following methods, 1. Deformed 2. Arrows 3. Contour Colors 4. Contour Node Lines Deformed Animation Deformed animation displays shapes as a deformation at each Point. This is normally used only with vibration or acoustic intensity data. •
If Animate | Deformation | Deformed at each Point.
•
If Deformation or Both is selected in the Deformation column of the SubStructure spreadsheet, those SubStructures will display deformed animation.
•
If Deformation or Both is selected in the Deformation column of the Points spreadsheet, those Points will display deformed animation.
is checked, shapes are displayed using deformation
Animation with Arrows Animation with Arrows displays shapes using an arrow at each Point. This is normally used only with vibration or acoustic intensity data. •
If Animate | Deformation | Arrows each Point.
•
If Arrows or Both is selected in the Deformation column of the SubStructure spreadsheet, those Substructures will display deformed animation using arrows.
•
If Arrows or Both is selected in the Deformation column of the Points spreadsheet, those Points will display deformed animation using arrows.
is checked, shapes are displayed using an arrow at
Contour Colors Contour Colors are used from the current Animation Source to display shape magnitudes on structure surfaces. Color contours are the primary means of displaying Scalar data on a model. All shape magnitudes within a band of values are displayed using the same color. •
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Contour colors are user-specified on the Contour Colors tab in the File | Options box of the current Animation source.
Tutorial #4 - Time-Based ODS Animation •
Contour Colors are displayed on each Substructure for the Measurement Type (Translation, Scalar, Machine Rotation, FEA Rotations) chosen in the Contours Data Type column of the SubStructure spreadsheet.
•
Contour Colors are displayed on each Surface for the Measurement Type (Translation, Scalar, Machine Rotation, FEA Rotations) chosen in the Contours Data Type column of the Surface Triangles or Surface Quads spreadsheet.
•
Execute Animate | Contours | Contour Colors the model Surfaces.
•
Execute Animate | Contours | Color Key to display the color key for the contour colors.
to display shapes using contour colors on
Contour Node Lines Contour Node Lines are lines where the shape magnitude is zero. Contour Node Lines are displayed on Surfaces just like Contour Colors. •
Execute Animate | Contours | Contour Node Lines
to display shape contour node lines.
Terminating Shape Animation •
Execute Animate | Draw Structure
•
Or execute Tools | Animate Shapes in the Animation Source window.
in the Structure window.
Animation is also terminated, •
If the current Animation Source window is closed.
•
Or a command is executed that modifies data in the current Animation Source window.
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Tutorial #5 - Documenting Results Making a Digital Movie A Digital Movie is a sequence of animation frames saved into a Microsoft Windows WMV file. The commands in the Movie Menu in the Structure window are used to create Digital Movies of any animated display in the Structure window or the entire Work Area. •
Movie files can be inserted into Windows Power Point slides and Word documents.
•
Individual animation frames can also be cut from a Digital Movie and pasted into documents.
•
Digital Movies are played back using the Windows Media Player.
•
Movie files can also be played on Apple, Unix, and Linux computers.
To create a Digital Movie, •
Hover the mouse pointer over the Demos tab to display the Demos fly out panel.
•
Move the mouse pointer over the panel to display the I-Beam.VTprj Project name, and double click to open the Project.
•
Execute Animate | Shapes | Compare Shapes to display two structures side-by-side in animation,
Notice that there are two Source lists on the Toolbar, (the Animation Source List and the Comparison Source List). Shapes from the Shape Table (SHP: Mode Shapes) are displayed on the left hand structure model, and shapes from the Data Block (BLK: FRFs) are displayed on the right hand model. •
Spin the mouse wheel to adjust the sizes of the two models, as shown below.
•
Execute Animate | Synchronize Shapes so that is checked.
•
Click on a Shape button in the Shape Table window.
Notice that the Line cursor in the Data Block window moves to the closest frequency to the shape frequency in the Shape Table.
Comparison of ODS & Mode Shape.
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Tutorial Volume IA - Basic Operations The ODS shown on the right hand structure is being dominated by the mode shape shown on the left hand structure. The MAC value = 1 on the red bar in the upper right corner indicates that the two shapes are identical to one another. •
Execute Movie | Make Structure Movie to open the Windows File Save As dialog box
•
Select a path and enter a movie name (or use the default path and name), and click on Save in the File Save As dialog box.
Next, the Make Movie window will open. •
Press the green Start button to begin making a movie.
Make Movie Window Showing the Start Button. During movie making, you can interact with the structure display using commands in the Structure window or in the current Animation Source window. •
Try rotating and zooming the display while the movie is being made.
•
Press the red Stop button in the Make Movie window to stop making the movie.
The Movie will be added to the Project as an Added file, and a window will open from which to play the Movie.
Movie Window.
The Windows Clipboard
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Tutorial #5 - Documenting Results The Windows Clipboard provides a means of copying text or graphics from any ME'scopeVES window into a Report file, or any other text, graphics or spreadsheet program. Any graphics that is displayed on the screen can be copied to the Windows Clipboard, and pasted from the Clipboard into another program. Copy Graphics to Clipboard The Structure, Data Block, and Acquisition windows have File | Copy to Clipboard | Graphics commands. These commands copy the current graphics in the window to the Clipboard as a Bitmap. Copying Spreadsheet Cells •
Select the spreadsheet cells for the intended cut, copy, or paste operation.
•
Hold down the Ctrl key and press the X key to Cut the contents of the selected cells to the Clipboard.
•
Hold down the Ctrl key and press the C key to Copy the contents of the selected cells to the Clipboard.
•
Hold down the Ctrl key and press the V key to Paste the contents of the Clipboard into the selected cells.
Save Graphics in a File
Execute the File | Save Graphics in a File command in the Structure, Data Block, and Acquisition window to save the window graphics into a disk file.
These graphics files can then be inserted in to a Power Point presentation or Word document, or into a Report file within ME'scopeVES.
Printing All ME'scopeVES data files can be printed to a Windows printer using File | Print commands in their respective windows. Both graphics and spreadsheets can be printed. These commands also print into a PDF file. Structure, Data Block, and Acquisition •
Execute File | Print | Graphics to print the contents of the graphics area, on the left side of the vertical blue splitter bar.
•
Execute File | Print | Spreadsheet to print the currently displayed spreadsheet, on the right side of the vertical blue splitter bar.
Shape Table •
Execute the File | Print commands in the Shape Table window to print either the Shapes (upper or left) spreadsheet or the DOFs (lower or right) spreadsheet.
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Glossary
A Acoustic Source: A group of Points on an Acoustic Surface containing measurements from an identified noise source. Sources are used for Source Ranking of acoustic data. Source names are entered in the Acoustic Source column in the Traces or Shapes spreadsheet. Acoustic Surface: A special type of SubStructure represented by a grid of measurement Points. Each measurement Point has a surrounding area and surface normal. Acoustic Surfaces are created with the Drawing Assistant. Active Graph: Either the upper or lower Traces in the graphics area on the left side of the Acquisition window. The upper or lower Traces are made active by clicking on them, or by executing Display | Active Graph in the Acquisition window. Active Traces: The Acquisition window displays upper & lower Traces in its graphics area. The upper Traces are time domain data acquired from the front end. The lower Traces are time or frequency domain measurements calculated from the upper Traces. The Display | Active Graph command toggles the active Traces between the upper & lower Traces. Active View: One of the four Views in the Structure window graphics area. Drawing operations like Move, Rotate and Resize are performed in the active View. A View is made active by clicking on it, or by executing on of the Display | View commands. Animation Equation: All animation is created in a Structure window by evaluating the Animation equations at each Point on a structure model. Each animation equation defines which measurements (M#s) are used to animate a Point in a direction. Animation equations are displayed on tabs above the Points spreadsheet by executing Edit | Animation Equations | Equation Editor in the Structure window. Animation Frame: Animation is created by displaying still pictures (frames) in rapid succession in a Structure window. The animation can be paused and stepped through the frames by using the Animate | Step commands. Animation Source: Any Data Block, Shape Table, or Acquisition window that is open in the Work Area. The current Animation Source is displayed in the Animation Source list on the Toolbar in the Structure window. During animation, M# data from the current Animation Source is animated using the Animation equations for each Point on the structure model. During a Comparison display, two Animation Sources are used. Auto spectrum: An Auto Spectrum is calculated by multiplying a Fourier spectrum by its complex conjugate. The Auto spectrum has magnitude only. Its phase is zero. An Auto spectrum can have either Linear (RMS) units or Power (MS) units.
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Tutorial Volume IA - Basic Operations
B Band Cursor: One of the Data Block window cursors, represented by two vertical lines on each Trace. Click & drag inside the band to move it. Click & drag outside the band to move the nearest edge of the band. Bitmap: A copy of the pixels used to draw the graphics in a window. Bitmaps are used in all Copy to Clipboard and Print commands that operate on graphics. Block Size: The number of samples (time or frequency values) in the Traces of a Data Block or Acquisition window. The current Block Size can be viewed and edited in the File | Properties dialog box. Increasing the Block Size appends zero valued samples to each Trace. Decreasing the Block Size removes samples from the high frequencies or time values of each Trace.
C Center Point: Any Point that is referenced in the Center Point column of the Points spreadsheet. A Point that references a Center Point is called a Radial Point. If a Center Point has a Machine Rotation Animation equation, all Radial Points that reference the Center Point will exhibit rotational motion about the Center Point during animation. Closely Coupled Modes: Two or more modes that appear as a single peak in a frequency domain function. This occurs when two or more modes have resonance curves that sum together to form a single peak. CMIF: CMIF is an acronym for Complex Mode Indicator Function. Peaks in multiple CMIF curves will indicate closely coupled modes and repeated roots. Modal participation factors are calculated along with the CMIFs, and are used in succeeding multiple reference curve fitting steps. CoMAC: CoMAC is an Acronym for Coordinate Modal Assurance Criterion. CoMAC indicates whether or not two shape components are co-linear for all (or selected) shapes in a Shape Table. If CoMAC > 0.9, the two shape components are similar (co-linear). If CoMAC < 0.9 the two shape components are different for all shapes. Complex Shape: A shape with components that have phases other than 0 or 180 degrees. During animation, complex shapes will exhibit a "traveling wave" motion. Complex shape components can be normalized (to phases of 0 or 180 degrees) using the Normalize Shapes coomands in a Strucutre, Shape Table, Data Block or Acquisition window. Contour: A locus of equal magnitudes of a displayed shape during animation. Contours are displayed only on surfaces of a structure model. Data Block Traces can also be displayed in a contour format. Cross spectrum: A cross-channel function, calculated by multiplying the Fourier spectrum of a waveform by the complex conjugate of the Fourier spectrum of another waveform.
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Glossary Cross-channel Measurement: A measurement function that is calculated between two different simultaneously acquired signals. Examples are Transfer Functions, Impluse Response functions, Transmissibility's, Cross spectra, Cross Correlations, and ODS FRFs. Current Animation Source: The Data Block, Shape Table, or Acquisition window that is currently used for animating shapes in a Structure window. The current Source name is displayed in the Animation Source list on the Structure window Toolbar.
D Data Block file: One or more Traces of measurement data with a common time or frequency axis. Time domain measurements are real valued. Frequency domain measurements are complex valued. Each Trace has a unique measurement number M#. M#s are displayed in the Select Trace column of the Traces spreadsheet, and are used by the Animation equations in a Structure window for retrieving shape data at the cursor position in a Data Block. DFT: DFT is an acronym for Digital Fourier Transform. The forward FFT transforms a sampled time domain waveform into its equivalent DFT. The inverse FFT transforms a DFT back into its equivalent sampled time waveform. If the time domain signal has N real samples, the DFT will have (N/2) complex samples. Digital Movie: A Windows video file that documents the animation in the Structure window. Digital Movies are made using commands in the Movies menu. Each Movie file is played back in its own window. A Movie is not saved in a Project but is attached to it as an Added file. DOF: DOF is an acronym for degree-of-freedom. A DOF includes a Point number & direction. If each measurement (M#) in a Data Block, Shape Table or Acquisition window has a DOF defined for it, the DOF can be used to create Animation equations by assigning M#s to Points & directions on a 3D model of the test article. Each Point number should correspond to a numbered Point on the model . Each DOF direction should correspond to a Measurement Axis direction at the Point on the model. Scalar data has no direction associated with it. Drawing Assistant: A set of tabs in the Structure window that are used for drawing and modifying structure models. The Drawing Assistant tabs are displayed above the SubStructure spreadsheet by executing Draw | Drawing Assistant. Drawing Object: A Point, Line, Surface, or SubStructure on a structure model. Each Point is defined by its global X, Y, Z coordinates. Each Line is defined between two Points, each Surface Triangle between three Points, and each Surface Quad between four Points. Each SubStructure is a collection of Points, Lines, and Surfaces. Driving Point: The DOF (Point & direction) where excitation is applied to a test article. A driving point measurement has the same Roving and Reference DOFs.
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Tutorial Volume IA - Basic Operations Driving Point Residue: A modal Residue is the numerator term or the "stength" of a mode in an FRF measurement function. A driving point Residue is obtained by curve fitting a driving point FRF measurement.
E EDS: EDS is an acronym for Engineering Data Shape, a general term used for any type of data measured from two or more points on a machine, structure, or acoustic surface. EMA: EMA is an acronym for Experimental Modal Analysis. During an EMA, the test article is artificially excited with either an impactor or a shaker. The excitation force and one or more responses caused by the force are simultaneously measured, and a set of FRF measurement functions is calculated The FRFs are then curve fit to obtain experimental modal parameters for the test article.
F FEA Assistant: A set of tabs in the Structure window that are used for drawing a structure model and adding FEA Objects to it. The FEA Assistant tabs are displayed above the SubStructure spreadsheet by executing FEA | FEA Assistant. FEA Object: FEA Objects are used by the SDM, Experimental FEA, and FEA Model Updating commands in ME'scope. FEA Objects are added between Points on a structure model. Their physical properties are defined in the FEA Properties window, and their material properties are defined in the FEA Materials window. FEA Rotations: FEA rotational data is used for SDM and FEA Model Updating calculations, and can be displayed in animation by executing Animate | Animate Using | FEA Rotations. FEA Rotational data is animated using FEA Rotation equations. Up to three FEA Rotation animation equations can be defined at each Point on a structure model. FFT: FFT is an acronym for Fast Fourier Transform. The FFT is an algorithm that transforms a uniformly sampled time domain signal into its equivalent Digital Fourier Transform (DFT). The Inverse FFT transforms the DFT back into its original sampled time domain signal. The FFT in ME'scope transfroms any number of samples, not just powers of 2 samples. Fixed DOF: A Fixed DOF on a structure model will not move during animation. Fixed DOFs are defined by executing Draw | Animation Equations | Fix DOFs. Fixed DOFs are removed by executing Draw | Animation Equations | Fixed to Interpolated. Fourier spectrum: A Fourier spectrum is the FFT of a uniformly sampled time waveform. The Fourier spectrum is also called the Discrete Fourier Transform, or DFT. FRF: FRF is an acronym for Frequency Response Function. An FRF is a cross-channel frequency domain function that defines the dynamic properties of a structure 100
Glossary between an excitation force DOF and a response DOF caused by the force. An FRF is defined as the ratio (response Fourier spectrum / force Fourier spectrum). The FRF is a special case of a Transfer Function, where the force is the denominator (Input) and the response is the numerator (Output) between to DOFs of a structure.
G Geometric Center: The average of the minimum & maximum coordinates in each direction (X,Y,Z) of all Points on a Drawing Object, FEA Object, or structure model. Global Curve Fitting: Global curve fitting processes multiple FRF Traces in a Data Block to obtain a global frequency & damping estimate for each mode in the measurement span or cursor band of interest. Group: Either Traces (M#s) in a Data Block or DOFs (M#s) in a Shape Table can be grouped together by giving them a common name in the Group column of the Traces or the DOFs spreadsheet. During shape animation, if the Animate | Animating Using | Groups command is enabled, then each Group is scaled separately so that data from two or more Groups can be displayed together.
I Input, Output, Both: These designations are used for MIMO modeling & simulation. When an FRF is calculated, the excitation force waveform is designated as the Input and the response waveform is designated as the Output. These choices are made in the Input Output column of the Traces spreadsheet. When Both is chosen, the waveform can be used as both an Input and an Output in MIMO calculations. Interpolated Equation: An Interpolated Animation equation is used to animate all unmeasured DOFs of a structure model. Interpolated Animation equations are created by executing Draw | Animation Equations | Create Interpolated. Interpolated equations are only used by animation when Animate | With Interpolation is enabled.
L Line Cursor: A Line cursor is one of the three toyes of Data Block or Acquisition window cursors. It is represented by a vertical line on each Trace. The Line cursor is moved by clicking & dragging on any Trace. Also, just clicking on a Trace will place the cursor at the mouse pointer position. Line Object: A Drawing Object, displayed as a straight line between two Points. Lines are displayed by executing Display Objects | Lines | Show Lines. All Line properties are displayed in the Objects spreadsheet by executing Edit | Object Type | Lines.
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Tutorial Volume IA - Basic Operations Local Curve Fitting: Local curve fitting extracts a modal frequency & damping estimate from each FRF Trace in a Data Block, for each mode.
M M#: M# is an abbreviation for Measurement number. Each Trace in a Data Block or Acquisition window has a unique M#. Also, each shape component (or DOF) in a Shape Table window has a unique M#. M#s are used by the Animation equations at each Point on a structure model to animate the Point using data from the M#s in the Animation Source. MAC: MAC is an Acronym for Modal Assurance Criterion. MAC indicates whether or not two shapes are co-linear (they lie on the same straight line). If MAC =1 the shapes are co-linear. If MAC > 0.90, the shapes are simlar (close to co-linear). If MAC < 0.90 the shapes are different. Machine Rotation Data: One of the kinds of shape data that can be displayed in animation on a structure model. Machine rotation data must be assigned to a Center Point in the Z-direction. During animation, all of the Radial Points that reference a Center Point are animated with rotation about the Center Point. Measured Equation: A Measured animation equation is a weighted summation of M#s that specifies which Trace M# or Shape component M# will be used to animate a Point & direction on a structure model. Animation equations can be viewed on the Animation Equation tab by executing Draw | Animation Equations | Equation Editor. They are also displayed at selected Points by executing Draw | Animation Equations | Show Equations. Measurement: A Trace in a Data Block or Acquisition window, or a shape component in a Shape Table. Each Trace or Shape DOF has a unique M#. Shapes are displayed in animation by evaluating Animation equations at each Point on a structure model. Measured Animation equations are created by assigning each M# to a Point & direction on the model. Interpolated Animation equations are created by assigning M#s from nearby Points to un-measured Points & directions. Measurement Axes: Each Point on a structure model has 3 Measurement Axes. Measurement Axes define the directions in which measurements were made at the Point. Measurement Axes are displayed and edited using the Measurement Axes tab, which is displayed by executing Draw | Animation Equations | Equation Editor. Measurement Set: A Measurement Set is all of the data that is simultaneously acquired during acquisition. Simultaneous acquisition requires simultaneous amplification, anti-alias filtering, and analog to digital conversion by a multi-channel acquisition front end. Measurement Sets are defined in an Acquisition window. Crosschannel measurements are calculated using data from the same Measurement Set. The current Measurement Set number is appended to the DOFs of all measurement functions calculated using the current Measurement Set.
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Glossary Meshing: Meshing subdivides selected Lines, Surfaces, FEA Objects, and SubStructures into more Objects. If a SubStructure is meshed, all of its Lines, Surfaces, and FEA Objects are meshed. The commands in the Draw | Mesh menu are used for meshing. MIMO model: A MIMO model is a Multiple Input Multiple Output frequency domain matrix model, where Inputs are multiplied by Transfer functions to obtain Outputs. A Transfer function matrix is multiplied by Fourier spectra of multiple Inputs to obtain Fourier spectra of multiple Outputs. Inputs, Outputs and Transfer functions can be calculated using different forms of the MIMO model equation. MMIF: MMIF is an acronym for Multivariate Mode Indicator Function. Peaks in multiple MMIFs will indicate closely coupled modes and repeated roots. Modal participation factors are calculated along with the MMIF curves, and are used in succeeding multiple reference curve fitting steps. Modal Model: A set of mode shapes that have been scaled so that they preserve the dynamic properties of a structure. Unit modal mass (UMM) scaling is used in ME'scope to create a modal model. A modal model is required for SDM amd FEA Model Updating. A modal model can also be used for FRF synthesis and MIMO Input & Output calculations. Mode Indicator Function: A mode indicator function is used for counting resonance peaks (or modes) in a set of frequncy domain functions. The number of modes in the data is then used for estimating modal frequency & damping using the Polynomial method. Mode Shape: Modes are used to characterize resonant vibration in structures. Each mode has a natural frequency, damping value, and a mode shape. The mode shape is a standing wave deformation of the structure at its natural (resonant or modal) frequency. An ODS for any time or frequency value is a summation of contributions from all of the mode shapes of a structure. mooZ: mooZ is the reverse of a Zoom operation in a Structure, Data Block, or Acquisition window. It restores the full display of the structure model in a Structure window, or the display of all of the Trace data in a Data Block or Acquisition window. MPC: MPC is an Acronym for Modal Phase Colinearity. The MPC has values between 0 & 1. If MPC = 1, all of the components of a shape lie on a straight line in the complex plane. If MPC < 1, the components do not lie on a strraight line. Lightly damped structures normally have mode shapes with MPC's close to 1. Multiple Reference Test: A Multiple Reference Test uses two or more fixed exciters to excite a test article, or two or more fixed response sensors. This is equivalent to measuring two or more columns (fixed exciters or Inputs), or two or more rows (fixed responses or Outputs) of the Transfer function matrix in the MIMO model.
N
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Tutorial Volume IA - Basic Operations Nodal Line: A Nodal Line is a line of the surface a structure where all shape components are zero. The Nodal Lines of a complex shape will move during shape animation, while the Nodal Lines of a normalized shape will not move. Normalized Shape: A Normalized Shape has shape components with phases of 0 or 180 degrees. During shape animation, a Normalized Shape will exhibit a "standing wave" motion, and its Nodal Lines will not move. Complex shapes can be normalized (have their phases rotated to 0 or 180 degrees) by executing Animate | Normalize Shapes in a Shape Table, Data Block, or Acquisition window.
O Octave: An Octave band is a frequency band where the highest frequency is twice the lowest frequency. Acoustic measurements are often displayed using 1/1, 1/3, or 1/12 octave bands. ODS: ODS is an acronym for Operating Deflection Shape. An ODS is the deformation of a structure at two or more DOFs due to its own operation and/or applied forces. A time domain ODS characterizes the structural deformation at a specific time. A frequency domain ODS characterizes the structural deformation at a specific frequency. An ODS for any time or frequency is a summation of contributions from all of the mode shapes of a structure. ODS FRF: An ODS FRF is a cross-channel frequency domain measurement that is obtained from operating data. It requires a Roving response and a (fixed) Reference response. An ODS FRF is created by attaching the phase of the Cross spectrum between the Roving & Reference responses to the Auto spectrum of the Roving response. ODS's can be displayed in animation directly from a set of ODS FRFs. Operating mode shapes can be extracted by curve fitting a set of ODS FRFs. OMA: OMA is an acronym for Operational Modal Analysis. An OMA is performed when the excitation forces are not or cannot be measured, and hence FRFs cannot be calculated. Cross spectra or ODS FRFs calculated instead of FRFs, and are curve fit to extract operating modal parameters. Operating Mode Shape: A mode shape obtained by curve fitting a set of output-only cross-channel measurements, either Cross spectra or ODS FRFs. Orthogonal Polynomial: Orthogonal Polynomial is an MDOF curve fitting method for estimating modal parameters from a set of FRFs. Modal frequency & damping estimates can be obtained by using either a Global or a Local version of this curve fitting method. Orthogonal Views: The Quad View in a Structure window displays four Views of the structure model, a 3D View and three orthogonal 2D Views (X View, Y View, and Z View). A single View is obtained by double-clicking on one of the four Views in the Quad View.
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Glossary
P Peak Cursor: A Peak cursor is one of the three Data Block or Acquisition window cursors. A Peak cursor is displayed on each Trace as a band with two vertical lines, and the Trace peak value in the band displayed with a red dot. Click & drag inside the band to move the peak cursor band. Click & drag outside the band to move the nearest edge of the band. Periodic Signal: The FFT assumes that the waveform to be transforming is periodic in its transform window (the samples used by the FFT). Traces that are completely contained within the transform window satisfy this criterion. Cyclical signals that complete an integer number of cycles within the transform window also satisfy this criterion. If a waveform is not periodic in its window, the transformed signal will have "leakage" (or distortion) in it. Photo Realistic Model: A Photo Realistic Model is a structure model that has digital photographs attached to its surfaces. Photo Realistic Models are created using third party software, and imported into ME'scope using the .OBJ file format. Point Matching: Point Matching is the process of matching and re-numbering Points and mode shape DOFs between an FEA model and an EMA model. Point matching is part of the FEA Model Updating option to ME'scope. Point Object: A Point Object is defined by its three global coordinates (X,Y,Z). Points are used as end points for defining all other Objects in the Structure window. Each Point has its own Animation equations that are used to animate the Point with shape data from an Animation Source (Data Block, Shape Table or Acquisition window). Point properties are displayed in the Objects spreadsheet by executing Edit | Object Type | Points. Pole: A pole is the frequency & damping pair for mode of vibration or structural resonance. Pole Plot: A graph of modal frequency versus modal damping estimates for several modes. Modal frequencies are plotted on the horizontal axis and modal damping values on the vertical axis. A pole plot can be displayed during Stability curve fitting, or from a Shape Table by executing Display | Poles. Project: All work in ME'scope is done with data in a Project file. A Project file can contain one or more Structure, Data Block, Shape Table, Acquisition, Program, Report, or Added files. Only one Project can be open in ME'scope at a time. All of the names of the data files in the currently open Project are displayed in the top (or left) pane of the Project Flyout panel. PSD: PSD is an acronym for Power Spectral Density. A PSD is calculated by dividing an Auto spectrum by its frequency resolution (the increment between frequency lines). PSD units are typically (g^2/Hz) or (g/(Hz^1/2))
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Tutorial Volume IA - Basic Operations Quad View: A Quad View of a structure model consists of four Views (X View, Y View, Z View & 3D View). The Quad View is obtained by double-clicking on a single View. Double-clicking on one of the Views in the Quad View will display only that View.
R Radial Point: A Radial Point is any Point that references another Point in the Center Point column of the Points spreadsheet. If a SubStructure has one or more Center Points defined for it, and Rotatation is set to Yes in the SubStructure Object spreadsheet, then during shape animation, all Radial Points will rotate about their Center Points. Also, if a Center Point has a Machine Rotation Animation equation defined for it, then during shape animation, all Radial Points will be animated with rigid body rotatation about the Center Point. Reference DOF: A Reference DOF is the fixed DOF in a set of cross-channel measurements. All cross-channel measurements should have both a Roving and a Reference DOF. The Reference DOF follows the colon in a measurement DOF = Roving DOF : Reference DOF. Repeated Roots: Two or more modes with the same modal frequency but different mode shapes is called a Repeated Root. Repeated Roots can occur in many types of geometrically symmetric structures such as disks, cylinders, square plates and cubes. Residue: A Residue is one of the three modal parameters (along with frequency & damping) obtained from FRF-based curve fitting. The model residue is the constant numerator term in the partial fraction form of an analytical FRF. It is also referred to as the "strength" of a resonance or mode. It carries the FRF engineering units multiplied by Hz (or radians per second). Each mode has a Residue matrix, which is associated with a corresponding MIMO model of the structure. The residues from one row or column of the Residue matrix define a Residue mode shape. Residue Mode Shapes: Residue mode shapes are created following curve fitting when the modal parameter estimates are saved into a Shape Table. Residue mode shapes can be scaled into UMM mode shapes if Driving Point Residues are present in the mode shapes. Residue mode shapes are also used to synthesize FRFs. Roving DOF: The Roving DOF is the DOF that changes in a set of cross-channel measurements. All cross-channel measurements have both a Roving DOF and a (fixed) Reference DOF. The Roving DOF preceeds the colon in a measurement DOF = Roving DOF : Reference DOF.
S Sampling Window: The Sampling Window is the time domain samples used by the FFT to calculate a DFT. The Sampling Window is also called the transform
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Glossary window. To create certain properties in its spectrum, a special time domain windowing function (Hanning, Flat Top, Exponential, etc.) may be applied to the samples in the Sampling Window prior to transforming them with the FFT. Scalar Data: Scalar data is one of the kinds of shape data that can be displayed in animation on a structure model. Scalar data has no direction associated with it. Examples of Scalar data include Sound Pressure Level (SPL), Sound Power, temperature, and pressure. Scalar data is animated on a structure model using color contours on surfaces. SDI: SDI is an Acronym for Shape Difference Indicator. SDI indicates whether two shapes have shape components with the same or different values in them. SDI values range between 0 & 1. If SDI =1.0 the shapes have identical shape components. If SDI < 1.0 the shapes have different shape components. Shape: A Shape consists of two or more measured or calculated values at DOFs on a structure or acoustic surface. Specific types of shapes are an Operating Deflection Shape (ODS ), mode shape, acoustic shape, and Engineering Data Shape (EDS). Shape components can be Translational, Rotational, or Scalar. For correct shape animation, all shape components must have correct magnitude & phase values relative to one another. Shape Interpolation: Shape components for each Point & direction on a structure can be Measured, Fixed or Interpolated. During animation, the shape components of Interpolated DOFs are calculated by evaluating Interpolated Animation equations. Interpolated Equations are created using neighboring Measured or Fixed DOFs. Interpolated Animation equations are created by executing Draw | Animation Equations | Create Interpolated. Shape Table file: A Shape Table is a file for storing shapes. An ME'scope Project file can contain multiple Shape Tables. A shape is a spatial description of data measured or calculated for two or more Points or DOFs on a structure or Acoustic surface. Shapes can be imported from an external source, saved from an Animation Source, saved from the Structure window during animation, or created by saving modal parameter estimates into a Shape Table. Sine Dwell: Sine Dwell in one of the three types of shape animation in ME'scope. During Sine Dwell animation, the displayed shape is animated by multiplying it by sine wave values. Single Reference Test: A Single Reference test uses a single fixed exciter or a single fixed response transducer during the test. If the exciter is fixed, the roving DOFs of response transducer define the components of the ODS's or mode shapes obtained from the measurements. If a fixed response transducer is used, the DOFs of the roving exciter define the components of the ODS's or mode shapes. A Single Reference test is equivalent to measuring one row or one column of the FRF matrix in the MIMO model of the structure. Single-channel Measurement: A Single Channel Measurement is calculated using data acquired from a single acquisition channel. Examples are a Fourier spectrum or an Auto spectrum. If multiple channels are simultaneously acquired,
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Tutorial Volume IA - Basic Operations then their Fourier spectra can be curve fit, and valid mode shapes extracted from them. Auto spectra can also be curve fit, but the resulting mode shapes will not have correct phases since the Auto spectra have no phases. SPL: SPL is an acronym for Sound Pressure Level. An SPL is a measure of the RMS sound pressure relative to a reference value. It is measured in logarithmic units of decibels (dB) above a standard reference level. A common reference level used is 20 ÎźPa RMS, which is considered the threshold of human hearing. Stability Diagram: A Stabiliy Diagram is created by pressing the Stability button on the Stability curve fitting tab. It is a graph of modal frequency & damping estimates for multiple curve fitting model sizes, from 1 to a Max. Model Size. All estimates that lie within user-specified tolerance limits are grouped into Stable Pole Groups. When the Save Stable Groups button is pressed on the Stability tab, the average value of the poles in each Stable Group is added to the Modal Parameters spreadsheet. Stationary Dwell: Stationary Dwell is one of the three types of shape animation in a Structure window. During stationary dwell animation, each shape is displayed without any animation. Stationary Dwell is most often used together with color contours for displaying acoustic shapes. Structure file: A Structure file contains the drawing Objects used to define a 3D model of a machine, structure, or acoustic surface. The structure model is used for displaying structural shapes in animation. Points, Lines & Surfaces are used for drawing 3D structure models and Acoustic Surfaces. FEA Objects can also be added between Points on the model. FEA Objects are used by the SDM, Experimental FEA, and FEA Model Updating commands in ME'scope. Structure Model: A Structure Model is used for displaying operating deflection shapes (ODS's), mode shapes, acoustic shapes or engineering data shapes in animation. A "stick model" consists of multiple Points connected by Lines. A "surface model" has triangular or quad surfaces added between Points. A "texture model" has textures defined for its surfaces. A "photo realistic model" has digital photographs attached to its surfaces. SubStructure: A SubStructure is a collection of Points, Lines, Surfaces, and FE Objects. SubStructures can be selected, moved, cut, copied & pasted like any other Object. SubStructure properties are displayed in the SubStructures spreadsheet. The Drawing Assistant is used to add SubStructures from the SubStructure Library to a model drawing. The FEA Assistant is used to add FEA Objects to SubStructures. SubStructure Library: The SubStructure Library is a special Project file containing predefined structure models. The Drawing Assistant is used to add SubStructures from the Library to a structure drawing. Any structure model can be saving into the Library by executing File | Save In Library in its Structure window. Surface Quad: A Surface Quad is a Drawing Object that defines a surface between four Points on a structure model. Surfaces are used for hidden line display, surface fills, surface textures, photo realistic models, and contour displays.
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Glossary Surface Quad properties are displayed in the Objects spreadsheet by executing Edit | Object Type | Surface Quads. Surface Triangle: A Surface Triangle is a Drawing Object that defines a surface between three Points on a structure model. Surfaces are used for hidden line display, surface fills, surface textures, photo realistic models, and contour displays. Surface Triangle properties are displayed in the Objects spreadsheet by executing Edit | Object Type | Surface Triangles. Sweep Animation: Sweep Animation is one of the three types of shape animation in a Structure window. During Sweep animation from a Data Block or Acquisition window, the cursor is moved through the Traces from left to right, and the data at each cursor position is displayed as a shape on the model. During Sweep animation from a Shape Table, each shape is displayed in succession using Dwell Animation and the number of dwell cycles from the Animation tab in the File | Shape Table Options box.
T Tool Tip: A Tool Tip is a brief description of each button (or Tool) on a Toolbar. If Help | Show Tool Tips is enabled, a Tool Tip will be displayed when the mouse pointer is hovered on a button. Trace: A Trace is one of the measurement functions displayed in a Data Block or Acquisition window. Each Trace has a unique measurement number (M#) associated with it, which is listed in the first column of the Traces spreadsheet. These M#s are used in the Animation equations on a structure model to display shapes directly from the cursor position in the Trace data. Trace Matrix: A Trace Matrix is a Data Block where each Trace Roving DOF designates the row, and each Reference DOF designates the column of the Trace in a matrix of Traces. Trace matrices can be manipulated using matrix algebra commands in ME'scope.. Transfer Function: A Transfer function is a cross-channel frequency domain measurement between an Output waveform and an Input waveform. A Transfer function is defined as the ratio (Output Fourier spectrum / Input Fourier spectrum). An FRF is a special case of a Transfer Function where the Input is a force, and the Output is caused by the force. Translational Data: Translational data is one of the kinds of shape data that can be displayed in animation on a structure modal. Examples of Translational data are vibration and acoustic intensity. Each Translational measurement has a direction associated with it. Measurement directions are defined by the Measurement Axes at each Point on the structure model. Up to three Translational measurements can be defined at each Point on a model. Transmissibility: Transmissibility is a cross-channel frequency domain measurement typically made from operating or output-only data. Transmissibility is defined as the ratio (Output Fourier spectrum / Input Fourier spectrum). Operating mode
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Tutorial Volume IA - Basic Operations shapes can be obtained by saving the cursor values at a resonant frequency in a set of Transmissibility's. A set of Cross spectra can be obtained by multiplying a set of Transmissibility's by a reference Auto spectrum.
U UFF: UFF is an acronym for Universal File Format. UFF is a disk file format used for exchanging data between different structural testing & analysis systems. Structure models (Points & Lines), mode shapes, ODS's, and time or frequency domain measurements can be imported & exported using UFF files. Typical UFF file name extensions are .UFF, .UNV and .ASC. UMM Mode Shapes: UMM Mode Shapes is a set of mode shapes that have been scaled to Unit Modal Masses. A set of UMM mode shapes is called a modal model, and it also preserves the dynamic properties of a structure. UMM mode shapes are used for SDM, FRF Synthesis, MIMO modeling & simulation, and FEA Modal Updating in ME'scope.
Z Zoom: Zooming enlarges the display of the model in a Structure window, or the Trace graphics in a Data Block or Acquisition window. A Zoom is initiated by executing Display | Zoom, or by clicking in the graphics area and spinning the mouse wheel.
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Index A
O
Acoustic Surface ................................ 27
Object List .......................................... 63
Add Object ................................... 63, 64
P
Animation speed ................................ 88
Point Animation ................ 44, 81, 85, 90
C
Points ........................................... 44, 58
Color................................................... 90
Q
Contours....................................... 90, 93
Quad View.......................................... 52
D
R
Drawing Object ............................. 45, 58
Resize ................................................ 21
Dwell Animation ........................... 33, 35
S
F
Shape ................................................... 1
Fixed Point ......................................... 81
DOFs spreadsheet.......................... 81
FRF .................................................... 75
Mode Shape ............................. 48, 93
G
Operating Deflection Shape .............. 1
Grid .............................................. 39, 54
Shape Animation ............................ 35
Group ................................................. 65
SubStructure ...................................... 51
I
Sweep animation ................................ 88
Import ................................................. 78
T
Interpolated Point ............................... 81
Time Domain Animation ........... 6, 31, 75
Interpolation ....................................... 88
Tracing ............................................... 70
L
Transmissibility ............................... 5, 75
Lines....................................... 51, 63, 70
U
M
UFF .................................................... 78
Measured Point .................................. 85
W
Mouse Operations .............................. 20
Work Area .......................................... 24
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