Taking Advantage of Technique by Kurt Brosnan

TAKING ADVANTAGE OF TECHNIQUE MATERIAL, FABRICATION, & THE GENERATIVE PROCESS

Kurt Brosnan Final Project Rensselaer Polytechnic Institute Spring 2009 Advisor Cluster: Jefferson Ellinger Ted Krueger Ivan Markov

TAKING ADVANTAGE OF TECHNIQUE

Abstract The contemporary practice of architecture has been subject to increasing influence from digital technologies and computation. Digital mediums provide a highly adaptable platform for design. They offer high levels of numerical accuracy and rapid iteration of design processes. With the use of rapid prototyping machines, and computer numeric controlled machining, digital designs may be quickly adapted for physical assembly; however without user input there is no account for material parameters in the digital process. The interest of this thesis is to understand the range of implications that component based assemblies have for architecture as a means of simplifying the process through which geometry is ultimately realized in fabrication. By adapting a generative process of design not only to material qualities, but to the techniques of machining and assembly used to manipulate those materials, there is a potential to realize opportunities wherein design may take advantage of material performance.

TABLE OF CONTENTS

Abstract ................................................................... i 1

Thesis Introduction ................................................. 2 material, fabrication, and the generative process

Understanding the Issues ...................................... 5 material process and component assemblies

Digital Fabrication .................................................. 11 methods and explorations

Material Performance ............................................ 41 adapting process to material parameters

Controlling the Variables ........................................ 51 process analysis and reflection Bibliography ............................................................ 59

THESIS INTRODUCTION

The properties of material may alter fabrication techniques and can dramatically impact the physical realization of a design. In this way an early adaptation of a design to issues of material and fabrication can bring out inherent flaws in design or may reveal interesting opportunities to drive the design in ways that may not have been foreseen at the onset of a project. The majority of the research in regard to this thesis has been performed in the area of modular or component assemblies for the definition of doubly curved surface geometries which are oriented toward a fabrication process which utilizes planar materials for rapid prototyping (laser cutting) and CNC milling. Because the machines or tools which are used in the fabrication process accept a particular type of data and have particular operations associated with the data it is necessary to understand that our digital process will ultimately need to be translated to the appropriate form of information in order to be fabricated. For example, in the case of laser cutting, the final output is a line or curve geometry which is read by the machine as points on a plane and intensity of cut. Relative to this idea, if we begin the design process by modeling surfaces, these surfaces will ultimately need to be cut into curves to be translated for laser cut assemblies. In a perfect design environment we could eliminate having to re-define our geometry for fabrication. Fabrication serves as an evaluation mechanism to understand the distinction between digital modeling informed only by end user software applications as opposed to the methods of digital modeling which are informed by physical assembly or fabrication. In certain cases a slight adjustment in process may alleviate many problems in the translation of a digital model to a physical assembly. Generative modeling tools have become quite useful in creating digital models which may be quickly iterated or adjusted. Adapting these tools to the fabrication techniques of a component based assembly can allow the designer to quickly adjust all aspects of the project from the digital model to the machining data and the final technique of assembly. Iterating through multiple approaches of this technique became useful to understand which material qualities and fabrication techniques may compound the design process. Through understanding and avoiding problem areas a technique was developed which appropriated material qualities to a simple pin connection. By adapting material performance to a simple connection the process between design and fabrication was radically simplified compared to many other techniques which were investigated.

MATERIAL, FABRICATION, & THE GENERATIVE PROCESS

UNDERSTANDING THE ISSUES

DOUBLE CURVATURE AND FABRICATION

Axel Kilian described this process in his study, “Fabrication of partially doublecurved surfaces out of flat sheet material through a 3d puzzle approach,” He proposed that there are primarily two approaches when investigating the application of fabrication techniques as they are related to the digital modeling environment. One method would be to “extract the capabilities of the machine and embed them into a generative program that explores the possible forms and cuts within the limitations” and the second method is to “design an object and adapt it to the machine’s capabilities.” (Kilian, 2000) The intent of the investigations of my work is not meant to be positioned within either of these techniques. Rather, they are directed toward developing a process of design which may take advantage of both material and machining capabilities. This is not to say that the work that I have pursued is necessarily different than Kilian’s it only means that my process was constrained in very different ways.

FIG. 1 KILIAN, 3D PUZZLE APPROACH

FIG. 2 KILIAN, 3D PUZZLE APPROACH

FIG. 3 KILIAN, 3D PUZZLE APPROACH BY UNDERSTANDING MATERIAL QUALITIES AND MACHINING TOLERANCE A COMPRESSION CONNECTION WAS DEVELOPED TO GENERATE CURVATURE OUT OF FLEXIBLE SHEET MATERIAL.

1 KILIAN, AXEL, “FABRICATION OF PARTIALLY DOUBLE-CURVED SURFACES OUT OF FLAT SHEET MATERIAL THROUGH A 3D PUZZLE APPROACH” (PHD CANDIDATE IN DESIGN 2 KILIAN, AXEL, “FABRICATION OF PARTIALLY DOUBLE-CURVED SURFACES OUT OF FLAT SHEET MATERIAL THROUGH A 3D PUZZLE APPROACH” (PHD CANDIDATE IN DESIGN 3 KILIAN, AXEL, “FABRICATION OF PARTIALLY DOUBLE-CURVED SURFACES OUT OF FLAT SHEET MATERIAL THROUGH A 3D PUZZLE APPROACH” (PHD CANDIDATE IN DESIGN

AND COMPUTATION, MIT, DEPARTMENT OF ARCHITECTURE), P.1) AND COMPUTATION, MIT, DEPARTMENT OF ARCHITECTURE), P.6) AND COMPUTATION, MIT, DEPARTMENT OF ARCHITECTURE), P.4)

MATERIAL PROCESS AND COMPONENT ASSEMBLIES

One of the primary issues when dealing with double curvature is the translation of curvature from the digital surface geometry into the physical model. In most types of assemblies the issue of curvature is addressed through the connection. When defining curved geometries in a physical model many of the connections may have very different angles of intersection. This issue is further complicated when dealing with two dimensional machining techniques as the cut plane is perpendicular to the material and results in a 90 degree edge on each side of the cut.

LAZER / WATTER JET MACHINING

2 DIMENSIONAL MILLING OPERATIONS

MATERIAL

90 CUT ANGLE

MACHINING BED

MATERIAL

90 CUT ANGLE

MACHINING BED

Kilian’s 3d puzzle approach was especially interesting case study because he was using material flexibility of the component rather than the components profile or section to help him define curvature of the model. The flexibility of the materials that Kilian explored allowed him to develop tolerances for a compression fitting. In order to do this he needed to understand the technique of assembly and the related material properties associated with that technique. He explored these issues through necessary iteration of the process from design to fabrication using new geometries and materials. Each test elicited new information that allowed him to understand the problem areas and develop methods to control those problems.

FIG. 4 KILIAN, 3D PUZZLE APPROACH

4 KILIAN, AXEL, “FABRICATION OF PARTIALLY DOUBLE-CURVED SURFACES OUT OF FLAT SHEET MATERIAL THROUGH A 3D PUZZLE APPROACH” (PHD CANDIDATE IN DESIGN

AND COMPUTATION, MIT, DEPARTMENT OF ARCHITECTURE), P.1)

UNDERSTANDING THE ISSUES

In my research I have explored a few main techniques for applying fabrication techniques to digital models. In most cases a free form surface was developed initially with only simple geometric criteria such as double curvature. The investigations focus on the methods of extracting data from the initial surface in order to adapt that data to a particular machining process. The data extraction methods investigated can be placed into a few categories and subcategories. 1.

2. 3. 4. 5.

NURBS Surface Segmentation a. Quadrilateral Panel Definition b. Triangular Panel Definition Curve and Panel Extraction Method Sectioning Method Planar Curve Mapping Local Component Mapping

Another very important part of this process was the connection. As discussed earlier, when dealing with double curvature the translation of that curvature into the physical assembly is ultimately addressed at the connection. Therefore the connection or method of assembly becomes extremely important. There were three primary techniques of assembly investigated throughout my work. These consisted of a tabbing technique, an interlocking connection, and a pin connection. Through multiple investigations which combined data extraction methods with machining and assembly techniques I began to develop my own understanding of the issues related to the fabrication of component assemblies.

MATERIAL PROCESS AND COMPONENT ASSEMBLIES

DIGITAL FABRICATION

N.U.R.B.S. SURFACE SEGMENTATION

One of the earliest design investigations was an exploration into the segmentation of NURBS (Non Uniform Rational Basis Spline) Surfaces as a method of eliminating curvature which are not possible to model with rigid planar materials. The images here are meant to illustrate how a base surface of three degree curvature may be redefined with quadrilateral panels eliciting a more angular geometry. As the number of panels increases (illustrated by moving from the top left to the bottom right in the images) the connection angles between the panels increase producing a more accurate definition of the original curvature. This method is reasonably accurate for creating flat quadrilateral panels as long as the surface curvature is synclastic. However, quadrilateral panels have the potential to retain some of the curvature of the original surface especially in the case of surfaces with anticlastic curvature. This is important because that curvature will be flattened during the fabrication process and produce inaccuracies in the physical model. These observations were made in later investigations in which a physical model was developed by connecting

CURVATURE ANALYSIS OF SEGMENTATION SHOWING DOUBLE CURVATURE IN CYAN OR RED

METHODS AND EXPLORATIONS

quadrilateral panels with a flexible tab connection. It was also learned that the problems presented by the quadrilateral panel may be addressed by further segmenting into triangular panels. With triangular panels there is no possibility for the original curvature to be retained in the subdivided panels. This was also discovered through the physical modeling process in an assembly using triangular panels with a tab connection as the method of assembly.

2 ORIGINAL SURFACE

DIGITAL FABRICATION

QUADRILATERAL PANEL MODEL

Once a digital method had been developed for creating flat quadrilateral panels to represent a doubly curved surface the next step of the process was to convert that information in to data which could be used to generate machining information to develop a physical model. Developing the physical model revealed that some of the curvature was being retained in the flat panels. This curvature was flattened out during the creation of the machining files. This created small problems expressed during the assembly process. While all of the panels were expected to lay flat, some were forced into slight curvatures in order to align their tabs for connection.

METHODS AND EXPLORATIONS

THIS MODEL DEVELOPED AS A FURTHER AUGMENTATION OF THE GENERATIVE MODEL IN ORDER TO CREATE MULTIPLE FENESTRATIONS OF THE SURFACE PANELS. THIS PROCESS WILL BE EXPLORED LATER IN A PHYSICAL MODEL USING TRIANGULAR PANELS INSTEAD OF QUADRILATERAL PANELS.

FABRICATION OUT OF A SINGLE FLAT SHEET OF MATERIAL. PANELS WERE ETCHED TO ALLOW FOLDING OF TABS TO BECOME CONNECTION ELEMENTS. SINCE THE ANGLES ARE SOLVED THROUGH THE TABBING METHOD THE PROCESS IS WELL ADAPTED TO THE PERPENDICULAR CUTS OF THE MACHINING PROCESS.

CONNECTION ANGLES OF THE TABS WOULD HAVE TO BE CONTROLLED IF THE MATERIAL WAS NOT ABLE TO BE BENT. HOWEVER FOR THIS SCALE THE TABBING METHOD WAS QUITE ACCURATE.

DIGITAL FABRICATION

TRIANGULAR PANEL MODEL

In order to address the issues of double curvature revealed by the quadrilateral panel model a new double curved geometry exhibiting anti-clastic curvatures was developed to test a triangular subdivision of the quadrilateral panel system. Because the triangular divisions are defined by only three points there is no potential for curvature to be retained in the final model. This is more easily noticeble on an anti-clastic geometry because the triangular component is able to bend in areas where the quadrilateral component could not. This forces the connection corners up or down depending on the direction of the surface curvature at that location. In the interest of understanding the effects of scale and material on the tabbing process another physical assembly was made of this geometry at a larger scale. A non-foldable material was used for defining the triangular panels. Because the component itself could no longer fold the connection needed to be made of a separate material. The complexity of this process became

Panel B3 Panel B2 Panel B1

Panel A3

Panel A2 Panel A1

Panel B6 Panel B5 Panel A6

Panel B4 Panel A4

Panel A5 Panel B7Panel A7

Panel B8 Panel B9

Panel A8

Panel A9

METHODS AND EXPLORATIONS

DETERMINING AND SETTING ANGLES IS SLIGHTLY INACCURATE

TRIANGULATION WILL ELIMINATE DOUBLE CURVATURE IN THE PANELS HOWEVER THIS WILL FURTHER ALTER THE DEFINITION OF THE ORIGINAL SURFACE

much harder to control. Templates were needed to guide the placement of the flexible connection pieces. This lead to inaccuracies in the physical assembly. These inaccuracies could have been easily controlled however the purpose of this investigation was simply to develop some sense of the issues involved with having separate components for panel and connection.

DIGITAL FABRICATION

PANEL & BEAM COMPONENT MODEL

The panel and beam component model was developed simultaneously with the quadrilateral and triangular panel investigations. This investigation was oriented more towards an investigation of the generative process. Curves and surface patches were extracted from the original surface geometry using a generative model that could control the size and depth of multiple members. The final assembly consisted of three kinds of components; panels, horizontal beams, and vertical beams, all of which were joined using an interlocking connection.

METHODS AND EXPLORATIONS

This method revealed the complications of having various kinds of components. With only three different kinds of components creating the machining data was much more difficult as location, orientation, and labeling of all of the parts must be kept in order.

DIGITAL FABRICATION

VERTICAL

CON-

NECTIONS

HORIZONTAL CONNECTIONS

PANELS

HORIZONTAL CONNECTIONS

VERTICAL

CON-

ASSEMBLY

NECTIONS

METHODS AND EXPLORATIONS

SIMPLIFIED COMPONENT SYSTEM FLEXIBILITY

SIMPLIFIED COMPONENT ANGLE FLEXIBILITY

DIGITAL FABRICATION

SECTIONING METHOD

The sectioning method of creating a module based on the straight sectioning of a predefined surface was investigated as another digital to physical process which involved the potential for some creative expression. In order to develop straight sections that could be flattened to generate machining data for the development of a physical model the original surface geometry must be intersected in specific ways. Many different approaches to the sectioning method were explored in order to find the most accurate representation of the original surface geometry. The final model was generated using sections taken radially from a centrally located point outside of the surface geometry.

135

120

110

HORIZONTAL SECTION VARIATIONS

135

110

120

140 150

45 30 20

VERTICAL SECTION VARIATIONS

METHODS AND EXPLORATIONS

FINAL SECTIONING METHOD USING POINT CENTRALLY LOCATED ALONG ORIGINAL SURFACE

GENERATION OF CUT DATA. PIECES ARE THE FULL LENGTH OF THE ORIGINAL SURFACE GEOMETRY . LARGER SCALES COULD BE FURTHER SUBDIVISION OF COMPONENTS WHICH WOULD REQUIRE A NEW TYPE OF CONNECTION SUCH AS A FINGER OR PUZZLE CONNECTION.

DIGITAL FABRICATION

Vs.

? GENERATION OF 90 DEGREE CONNECTION TO ADAPT TO PERPENDICULAR CUT OF MACHINING PROCESS. IT IS IMPORTANT TO RETAIN STRAIGHT SLICES THROUGH THE ORIGINAL SURFACE IN ORDER TO MAINTAIN COMPONENTS WHICH WILL NOT BE ALTERED BY LOSS OF INFORMATION DURING THE MACHINING PROCESSES.

OFFSETS OF THE ORIGINAL SURFACE MUST BE CAREFULLY CONTROLLED TO CREATE DEPTH OF THE SECTION CURVES. THIS MUST RESPOND TO MATERIAL PROPERTIES AND MACHINING TOLERANCES OTHERWISE THE RESULTING COMPONENTS MAY BE TOP THIN OR TOO BULKY.

Connection at Ground

METHODS AND EXPLORATIONS

DIGITAL FABRICATION

SECTIONING METHOD

This exploration looks to a alternate geometry than the previous methods to understand how building a geometry that has curvature which is not bending out of plane can be solved more easily than the previous geometry which has multiple curvatures that are defined outside of two axis. The geometry was developed with a simple algorithm which would generate lines which were only bending in specific directions. This proved much easier to solve and the cut data could be taken directly from the geometry rather than having to be unrolled and repositioned. This was helpful in illustrating how slight adjustments in digital technique can constrain design in ways which will ease the transition into the physical assembly.

top

Front

Isometric

Right

METHODS AND EXPLORATIONS

DIGITAL FABRICATION

MATERIAL FLEXIBILITY

The next series of investigations were quick studies into the qualities of flexible planar materials. Each of the investigations seeks to understand how the flexibility of the material can begin to support the assembly process by defining the curvature through the material rather than relying entirely on the machining of the material or the connection of the components to generate the desired curvatures. The digital techniques vary greatly throughout these studies. In some cases there was very little development of a digital process because the studies were directed toward understanding the potential for material performance which is most easily understood through material investigation.

OVERLAPPING CONNECTIONS

This was a quick technique of mapping planar curves onto a surface geometry and unrolling the resulting component geometries so that they may be machined and assembled. The overlapping arms of the model create a kind of friction connection that allow the bent pieces to hold each other into place. In this way the curvature of the original surface geometry is providing structural support in the connection of the component parts. Because each component must be bent into position the forces exerted create friction with its neighboring components to allow it remain in place.

METHODS AND EXPLORATIONS

BENDING THROUGH NETWORK

The integration of pin connections and stiffeners of varying lengths was used in this study to institute curvature throughout a material network. A simple four ply pattern was developed through which the plies were separated using a stiffening element. This model was essentially a more physical sketch to understand potential material properties before entering the digital design environment. It represents a time in investigation period were it became much easier to make quick sketch models to get a quick idea of how material performance would effect the potential design of a digital model.

DIGITAL FABRICATION

FLEXIBLE STRIP MODELS

These explorations were developed to understand how a flexible strip component could be implemented in certain ways to define a surface geometry. The first test used a controlled geometry that resulted from a radial array of twelve identical strips in two opposing directions to create a surface. The bending of the strips provides structural stability of the overall geometry. This study developed interest in creating the same effect across a non-symmetrical geometry. The second model is an exploration into propagating strips between four free-form curves in a way that would force them into bending and provide

METHODS AND EXLPLORATIONS

structural integrity of the system. While the results of the second study revealed interesting results there was great difficulty in controlling the system. Branching out from these more materially driven component studies a new investigation was developed into the adaptation of flexible material to a generative process. By combining the concepts of these flexible component investigations with the rapid iteration of a generative model the investigation may be taken back into the levels of controlled originally presented by a generative digital model. This level of control may allow a more precise transition of digital data into the process of machining and generation of a physical model.

DIGITAL FABRICATION

FLEXIBLE COMPONENT MODEL

Combining the previous studies of material flexibility with a generative process would allow for the quick transition from a digital model into machining data and physical assembly that was explored in the earlier generative investigations. In order to do this a new technique related to the surface segmentation techniques was deployed. With this technique the original surface geometry is defined using a predefined component module. A module of certain dimensions can is described by its location on a local quadrant plane. The local component quadrant is then referenced to each quadrilateral subdivision of the original surface geometry and scaled into its appropriate position on the surface.

METHODS AND EXLPLORATIONS

The initial model was created using a thin coated paper which was glued together. The relative ease of transition from digital model to physical assembly and the control of component definition along with the generation of machining information led to a prototype test of this process at a much larger scale. The potential for this method was still unknown however by moving to a larger scale it would become more evident what the architectural implications of this technique could become.

DIGITAL FABRICATION

SCALE PROTOTYPE

In developing a scale prototype of the previous model a few adjustments needed to be made in the design process. The orientation of the previous module was in an “X” direction. The new model was to be developed out of quarter inch laminated material. The “X” orientation of the module in this case would create approximately one inch of overlap at the connection locations. This seemed intuitively problematic. By adjusting the orientation of the component to a “+” or cruciform condition the overlap would be cut in half at the connection locations. This condition seemed intuitively less problematic than the conditions created by the”X” orientation of the module.

COMPONENT VARIATIONS

METHODS AND EXLPLORATIONS

Once this had been done a new test geometry was developed. The curvature of this geometry was essentially developed from an intuition of the potential for the material to perform. The new component orientation was mapped to the new surface geometry so that the number of subdivisions left a consistent degree of overlap of each component module. Once again because this was an initial prototype there was no direct information to base decisions on so most decisions were made given an intuition of material performance. With the geometry and component mapping decided the next step was to develop labels and addition mappings for the machining and assembly process. Because of the material thickness the machining was more appropriate for the CNC milling machine rather than the lazer cutter. This allowed for point data to be mapped to specifically respond to the drilling operations of the mill. By mapping point data to the connection locations of the components a simple drilling operation could create a control location to which each component could be aligned into its appropriate position on the global geometry.

90 TOTAL MODULES

12.00

DIRECTION OF STRIP ASSEMBLY

12.00 36.00

60.00

72.1 1

6 MOD-

15 MODULES 68.00

BASIC SURFACE GEOMETRY

SURFACE WITH MAPPED COMPONENTS COMPONENT DIVISION BASED ON OVERLAP AT SEAMS

DIGITAL FABRICATION

The machining and assembly process was completely organized using the generative model. Each component along with its machining information and assembly labels was laid out using a single generative model. This allowed many parameters to be quickly monitored and adjusted if necessary. All of the components were machined from approximately five four foot by eight foot sheets of material. Once all of the components had be machined and labeled new challenges developed in the method of assembly. The technique of assembly with this model is still an area which could use more investigation. For this model the components were initially assembled in strips. These strips were then â&#x20AC;&#x153;zippedâ&#x20AC;? together using a process which combines a lever mechanism to align the connection points and a clamp to force the pieces into position. It is important to make note here that further investigation into alternate methods of assembly could produce some interesting results; perhaps alleviating some of the difficulty of the assembly process employed.

Point geometry to set drilling operations exterior curves for outside profiling

arm labels for assembly

x28

component lable

interior curves for inside profiling

MILLING OPERATIONS AND FABRICATION LAYOUT

METHODS AND EXLPLORATIONS

Once the pieces were forced into position and pinned together the curvature of the original surface geometry was taken up by the flexible material. The decision that were made on intuition alone were fortunately accurate for this test model. None of the components were forced into a position that led them to failure. Understanding the results of material testing that will be covered later in the process showed that some of the pieces were in fact quite close to exceeding the limits of the material. The success of this investigation drove the successive work in a much more specific direction. Interest into developing an understanding of material potential for this type of assembly to be created out of greater thicknesses of material led to material testing investigations which will be covered in the following chapter. In order to develop a design at a new scale it became necessary to develop an understanding of material performance.

INITIAL STRIP ASSEMBLY

PIN CONNECTION TEST MODEL

SURFACE CURVATURE TAKEN BY MATERIAL

CONNECTION DURRING ASSEMBLY SURFACE CURVATURE TAKEN IN THE JOINT

CONNECTION DURRING ASSEMBLY PINING, CURVATURE TRANSLATED THROUGH MATERIAL

DIGITAL FABRICATION

METHODS AND EXLPLORATIONS

MATERIAL PERFORMANCE

MATERIAL TESTING

Following the development of the previous model the focus of the work was directed toward creating some kind of material input into the design process. In order to do this, based on examining the way in which the material was performing in the previous model, the best testing mechanism seemed to be to evaluate the materials based on their bending performance. If an understanding of the relationship between span and deflection could be determined then many of the controlling factors could be understood and accounted for in the creation of a new design. Several material tests were performed using a Universal Testing Machine in order to monitor how load was effected by span, width of material, thickness of material, as well as type of material. Since the previous model was built using a 5-ply quarter inch laminated material the tests were more adjusted toward continuing investigation of materials of a similar variety. However an additional oriented strand material was tested to create data that would allow the data of one material to be evaluated based on the performance of the other.

BENDING TEST EXAMPLE OF TESTS CONDUCTED USING A SIMPLY SUPPORTED MODULE ACROSS AN EIGHT INCH SPAN

BENDING TEST EXAMPLE OF TESTS CONDUCTED USING A SIMPLY SUPPORTED MODULE ACROSS A SIXTEEN INCH SPAN

ADAPTING PROCESS TO MATERIAL PARAMETERS

b( h^ 2) /6

W id th

l M at er ia

Th i

ck ne ss

Span (in)

(in)

8 L(1) Deflection

Load

(in)

(lb)

0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.48

6.97 19.56 30.24 40.58 50.7 61.04 70.48 78.24

Deflection E

6.97 12.59 10.68 10.34 10.12 10.34 9.44 7.76

Notes

Increments

(lb)

285491.200 w/ grain 534118.400 619315.200 664862.720 692224.000 714342.400 721715.200 712157.867 Failure

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6

f(b) = M/W

0.25

5ͲPlyy Imperial Birch Plywood

Load

(in)

AVG 10.17333333

0.020833333

16 L(2)

Increments

1.461 5.284 8.993 12.59 16.41 19.9 23.72 27.88 31.03 34.17 37.1 40.36 42.72 45.08 46.2 48 48.35 49.1 51.37 52.84 52.9 53 53.4 54.52 54.6

1.461 3.823 3.709 3.597 3.82 3.49 3.82 4.16 3.15 3.14 2.93 3.26 2.36 2.36 1.12 1.8 0.35 0.75 2.27 1.47 0.06 0.1 0.4 1.12 0.08

Notes

478740.480 *cross grain 865730.560 982275.413 1031372.800 1075445.760 1086805.333 1110367.086 1141964.800 1129767.822 1119682.560 1105175.273 1102097.067 1076806.892 1055129.600 1009254.400 983040.000 931960.471 893838.222 885943.242 865730.560 825441.524 Holding 789410.909 760787.478 744379.733 715653.120 Failure

AVG 3.77414286

0.041666667

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55

15.85 39.01 61.83 82.51 101.5 118.4 137.2 148.7 163.5 172 180

15.85 23.16 22.82 20.68 18.99 16.9 18.8 11.5 14.8 8.5 8

649216.000 798924.800 844185.600 844902.400 831488.000 808277.333 802816.000 761344.000 744106.667 704512.000 670254.545 Failure

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6

AVG 19.6

5.958 12.82 19.9 26.76 33.5 40.24 46.88 51.92 57.11 63.18 68.91 79.03 86 82 96 100 103

5.958 6.862 7.08 6.86 6.74 6.74 6.64 5.04 5.19 6.07 5.73 10.12 6.97 Ͳ4 14 4 3

976158.720 *cross grain 1050214.400 1086805.333 1096089.600 1097728.000 1098820.267 1097259.886 1063321.600 1039655.822 1035141.120 940851.200 924876.800 880640.000 746382.222 786432.000 744727.273 703146.667 holding

AVG 6.82033333

5 Ply- 1/ 4"" -5I P mpe ly- r1/ ia l4"" Bir -chI mpe Plyw roo ia ld Birch Plywoo d

2" 4"

5 0

200 180 160 140 120 100 80 60 40 20 0

12 10

2" - 8" Length 4" - 8" Length

0.2

0.3

0.4

0.5

6 4 2

2" - 16" Length

4" - 16" Length

-2 -4

0.1

Force (lb)

Lengt h

-6

0.6

0.5

1.5

(in)

2.5

(in)

5 Ply- 1/ 4"" 5-P I l mp y-e1/ ria 4"" lBir -cI h mp Plyw eria oo lBir d ch Plywoo d

ly- r 1/ 4"" -ch I mpe rioo a lB d 5 Ply- 1/ 4"" 5 -P I mpe ia lBir Plyw dirch Plywoo

200

120

180 100

160 140

60 2" 40

Force (lb)

80 Force (lb) b)

Force (lb)

lmp y- e 1/ 4"" I mp ia lBd irch Plywoo d 5 Ply- 1/ 4""5-PI ria lB-ir c h Ple yr w oo

5 Ply- 1/ 4" - I mperia lBir ch Plywoo d

Lengt Lengt h h

120 100 80

20 0

0 0

0.5

1.5

2 (in)

2.5

0.1

0.2

0.3

0.4

0.5

0.6

(in)

MATERIAL PERFORMANCE

2) h^ b(

W id

ick Th

Deflection

Load

Increments

(in)

(lb)

at er ia l

Span (in) 8 L(1)

(in)

Increments

(in)

(lb)

117411.840 *cross grain 265932.800 346862.933 389683.200 432128.000 439808.000 Failure

5.733 20.237 24.84 25.3 50.49 45.2

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 1.15

AVERAGE

4.6 11.02 17.31 23.38 29.34 35.3 41.14 46.88 52.84 58.91 64.08 68.8 73.41 76.22 80.15 83.3 85.1 87.35 88.13 90.12

E Notes

4.6 6.42 6.29 6.07 5.96 5.96 5.84 5.74 5.96 6.07 5.17 4.72 4.61 2.81 3.93 3.15 1.8 2.25 0.78 1.99

376832.000 451379.200 472678.400 478822.400 480706.560 481962.667 481455.543 480051.200 480961.422 482590.720 477221.236 469674.667 462595.938 445995.886 437725.867 426496.000 410081.882 397539.556 379979.453 369131.520 Failure

331971.129

AVERAGE

0.025 0.05 0.075 0.1 0.125 0 15 0.15 0.175 0.2 0.225 0.25 0.266

0.166666667

432639.339 8.544 38.67 85.66 135.8 186 235 6 235.6 281.8 324.8 365.7 401.6

8.544 30.126 46.99 50.14 50.2 49 6 49.6 46.2 43 40.9 35.9

87490.560 *cross grain 197990.400 292386.133 347648.000 380928.000 402090 667 402090.667 412233.143 415744.000 416085.333 411238.400 Failure

0.05 0.1 0.15 0.2 0.25 03 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.839

7.869 20.57 33.16 46.53 59.24 70 71 70.71 82.96 94.77 106.7 117.5 129.2 137.4 149.9 155.8 167.5 176.4

7.869 12.701 12.59 13.37 12.71 11 11.47 47 12.25 11.81 11.93 10.8 11.7 8.2 12.5 5.9 11.7 8.9

322314.240 421273.600 452744.533 476467.200 485294.080 482713 482713.600 600 485434.514 485222.400 485603.556 481280.000 481093.818 468992.000 472300.308 455826.286 457386.667 451584.000 Failure

P - 1/2"" -I mp eri al B Plywood 9P9 ly -ly 1/2"" -I mp eri al B irc hirc Ph lywood

9Ply- 1/2"" 9-Ply I mp -e 1/2"" ria lB -irc I mp hPe lywood ria lBirc hPlywood

9Ply- 1/2"- I mperi a lBirchPlywood

Leng Lth ength

LeL ng eng thth

60 50

450

400 350

30 20

10 8

300 Force (lb)

Force (lb)

250

2" - 8" Length

200

4" - 8" Length

150

2" - 16" Length

100

4" - 16" Length

0 0

0.1

0.2

0.3

0.5

1.5

0.5

1.5

(in)

9-PI lmp y- e 1/2"" I mp ria lBirchPlywood 9Ply- 1/2"" ria lB-irc h Ple ywood

9Ply- 1/2""-9I P mp ly-er 1/2"" ia lBir -chI mp Plywood eria lBirchPlywood 450

200

400

180

350

160 140

250 200

150

Force (lb)

300 Force (lb)

Force (lb)

Load

0.083333333

5.733 25.97 50.81 76.11 126.6 171.8

Deflection Notes

0.5

9ͲPly Baltic Birch Plywood

0.025 0.05 0.075 0.1 0.15 0.2 0.223

16 L(2) E

120 100 80

100

0 0

0.1

0.2 (in)

0.3

0.5

1.5

(in)

ADAPTING PROCESS TO MATERIAL PARAMETERS

0.063802083

b (in)

h (in)

Deflection

0.127 7604167

0.4375

Oriented Strand Board (OSB)

^2 )

id th

b( h

Th i

M at er

ia l

ck n

es s

Span (in)

Load

8 L(1) Increments

(in)

(lb)

0.025 0.05 0.075 0.1 0.15 0.2 0.25 0.3 0.33

4.047 11.58 19.9 27.77 43.17 58.57 67.9 77.68 79

0.03 0.05 0.08 0.10 0.15 0.20 0.25 0.30

8.77 27.99 51.82 76.67 124.60 167.40 194.80 170.00

Deflection Notes

4.047 7.533 8.32 7.87 15.4 15.4 9.33 9.78 1.32 Failure

8.768 19.222 23.83 24.85 47.93 42.8 27.4 Failure

16 L(2) Increments

Load

(in)

(lb)

Notes

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.87

3.597 8.5 12.8 17.2 20.9 25.5 29.23 32.8 34

3.597 4.903 4.3 4.4 3.7 4.6 3.73 3.57 1.2 Failure

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

10.45 21.13 31.25 41.26 51.04 58.91 68.8 77.45 84.54 89.9 91.39 95

10.45 10.68 10.12 10.01 9.78 7.87 9.89 8.65 7.09 5.36 /holding 1.49 /holding 3.61 Failure

AVERAGE

27.400

7.686

7/ 16" - Ori ented Stra nd Boa rd

7/ 16" - O 7/ ri e 16" nte-dO Sri tr e a nt nded Bo S a trd a nd Boa rd

100

250

90 80

200

Force (lb)

100

4" 50

60 1/8 Width to length

50 40

20 10

1/4 Width to Length

0 0

0.1

0.2

0.3

0.4

0.5

(in)

1.5

(in)

7/ 16" - Ori ented Stra nd Boa rd

7/ 16" - O 7/ ri 16" ent-edOS ri te ra nt nd edBS ota rr a d nd Boa rd Ac ro ss Ac 8" ro L ss en 8" gt Lhength

Ac ro ss16" Length

30 2"

Force (lb)

70 150

1/8 Width to length

1/4 Width to Length

0 0

0.1

0.2

0.3 (in)

0.4

0.5

1.5

(in)

MATERIAL PERFORMANCE

(in)

(lb)

0.26 60416667

0.625

Oriented Strand Board (OSB)

Load

0.130208333

Deflection

^2 ) b( h

Th i

M at er

ia l

ck n

id th

es s

Span (in) 8 L(1) Increments

0.025 0.05 0.075 0.1 0.125 0.15 0.175 0.2

8.094 57.11 118.7 179.9 237.5 287.8 326.8 270

0.025 0.05 0.075 0.1 0.125 0.15 0.175 0.2

13.38 85.32 180.1 275.5 361.9 452.3 537.6 545

Deflection Δ

(in)

(lb)

Notes

8.094 49.016 61.59 61.2 57.6 50.3 39

Notes

0.1 0.2 0.3 0.4 0.49

32 66.55 98.5 130 131

32 34.55 31.95 31.5 1 Failure

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 05 0.5 0.55

32.7 65.31 97.91 130.1 161.9 190.7 219.7 247.1 273.1 291 6 291.6 312

32.7 32.61 32.6 32.19 31.8 28.8 29 27.4 26 18 5 18.5 20.4 Failure

Failure

13.38 71.94 94.78 95.4 86.4 90.4 85.3 7.4 Failure

AVERAGE

68.125

28.364

5/8" - Oriented St randBoa rd

5/8" - Or 5/8" iented -O St rir ented a nd Bo St a r r a dnd Boa rd 600

350

500

300

300 2"

200

Force (lb)

250

400

100

200 150

100

50 0

0 0

0.05

0.1

0.15

0.2

0.25

0.2

0.4

5/ 8" - Ori ented Stra nd Boa rd

5/8" - O5/8" riented - OSt riented ra nd BSt oa ra rd nd Boa rd Ac ro ss Ac 8"ro Len ssg 8"thLength

120

0.6

(in)

Ac ro ss16" Length

40 35

100

60 2"

4" 20

Force (lb)

30 80 Force (lb)

Force (lb)

Load

16 L(2) Increments

25 20 15

5 0

0 0

0.1

0.2 (in)

0.3

0.2

0.4

0.6

(in)

ADAPTING PROCESS TO MATERIAL PARAMETERS

In order to adapt the material testing to the digital model a generative model was developed to evaluate the approximate bending through each local component quadrant. Once this model was developed the maximum and minimum deflection relative to span could be determined for the design of any surface geometry. Through the information gathered in the bending tests an approximate modulus of elasticity of each different material was determined using the formula for the allowable deflection. P p*L3 = 48*E*I = deflection L p = load L = span E = modulus of elasticity h I = b*h b 12 Using the same formula for allowable deflection and substituting the values determined for modulus of elasticity it is possible to solve for deflection using the spans of the subdivisions of the surface geometry. By comparing the calculated deflections with the deflections shown by the digital model it is possible to develop an understanding of whether or not the subdivision of the surface geometry is allowing deflections within the capabilities of material performance. To establish the accuracy of these tests the material performance of similar materials that had been documented were evaluated. This determined that the testing had produced relatively accurate results and the data could be trusted for the development of a new model. However there were still many issues of flexibility throughout greater thicknesses of the laminated material. Also it be-

GENERATIVE MODEL APPROXIMATE BENDING THOROUGH LOCAL SURFACE QUADRANT

MATERIAL PERFORMANCE

came evident later in the design process that many other factors, related to the component geometry and proportions, were more important than the evaluation of the material capabilities in bending alone. The bending tests however produced accurate results and the testing resulted in a data set that allowed the incorporation of material parameters in the design process which was the ultimate goal of the investigation.

GENERATIVE MODEL MAXIMUM AND MINIMUM DEFLECTION ACROSS BASE GEOMETRY

ADAPTING PROCESS TO MATERIAL PARAMETERS

BY MEASURING THE CURVATURE AND SPAN OF THE GLOBAL GEOMETRY AT THE LOCAL REGIONS OF EACH COMPONENT THE NECESSARY RELATIONSHIPS OF MATERIAL THICKNESS AND PROPORTION OF THE COMPONENT GEOMETRY MAY BE DETERMINED

CONTROLLING THE VARIABLES

MOVING FORWARD

In continuing design explorations after the material testing many issues were still left unaddressed. Further investigations were pursued in understanding the relationship of the component geometry to potential structural characteristics of the final model. Generative models were developed to support various tilings of component geometries. The interest of these studies was in how bending could potentially be translated in the final fabrication and where potential stress areas could be controlled by the component geometry. A final component geometry was determined based on a simple diagram of bending within a local component. This geometry was not tested before developing the final model which resulted in the inaccuracies of the final model. It is important to establish a test model for every iteration of the design process. The understanding was that the final component geometry would switch from a pinned to a fixed condition. This would increase the structural performance of the component. However it had tremendous impacts on the final assembly.

PROCESS ANALYSIS AND REFLECTION

The development of the final model was positioned around the expected performance of the new component geometry. Since a test had not developed the ultimate inaccuracies exhibited in the final model were proof to the necessity of a test model. The new component would not perform in the same manner as the old component. Curvature would be translated through the material in ways that were very different than that of the previous studies. This would not allow for the definition of the geometry that was exhibited in the previous model. While the bending tests were accurate in defining the material performance they could not account for the translation of forces that were determined by the new component module. Portions of the final model still performed in ways that were exhibited in the previous model however, the accuracies of the final model were very much altered by the component geometry. Overall the processes explored were extremely interesting for the practice of architecture. The lack of material constraint exhibited by digital methods is a serious flaw in the design process. By adding simple data to a generative process component based assemblies may be manipulated to allow them to be quickly adapted to physical design or assembly criteria. The focus here must be on the development of accurate tests to ensure the accuracy of material data in the process of design. There are many aspects which effect the ultimate outcome of the process. Even when accounting for material issues in the design process, many geometric issues may go overlooked or unforeseen. Developing an adequate testing mechanism for a design is essential. Without an adequate testing mechanism many consequences in the fabrication process may go unforseen. By developing small scale tests problem areas may be avoided before they become a part of a final product.

Curvature taken by component through single connection

Surface Geometry

Curvature taken by component through double connection

Surface Geometry

CONTROLLING THE VARIABLES

FINAL MODEL DESIGN PAVILION EXPRESSING SEVERAL CHARACTERISTICS OF COMPONENT CAPABILITIES INCLUDING DOUBLE CURVATURE BIFURCATION AND SPECIFIC PERFORMANCE

PROCESS ANALYSIS AND REFLECTION

The importance of this process is exhibited in the material performance of the earlier models and the process of investigation. The overall success of the techniques explored in this design process exhibit the importance of integrating material properties to design. By understanding the material implications of a digital process a physical model may be developed which allows for quick adaptation to a physical process. There are many interesting qualities and material performances that were stumbled upon throughout all of the investigations of this process. If there is anything to derive from these studies it is that no matter what the advancement of digital techniques the integration of physical parameters in the design process will be essential. Even if material parameters are eventually considered in the digital process material exposure and intuition will ultimately determine the success of a final design. The best method for accounting for this in the design process is to develop multiple tests at every phase of the design no matter how inconsequential it may seem. With the importance of a test model realized the next important and influential part of the process was the technique of assembly. This was another area which could use considerable investigation. As was stated earlier, the technique of assembly used in the scale prototype model was one in which individual components were connected in strips and the strips were connected to form the overall surface. While this process was successful it was quite labor intensive. This same technique was carried out in the final model however the final component geometry made assembly in this manner much more difficult. Moving forward with these investigations the impacts of the technique of assembly and planning for that technique in the design process could inform the studies a great deal. The techniques pursued in these investigations have resulted in many interesting discoveries. Hopefully the work may serve as a valuable reference for others who are interested in pursuing similar methodologies in the design process. The ultimate performance of any fabrication is exhibited through a material assembly. If we are to design with material we must realize the importance of material performance and develop an understanding of the material qualities we wish to emphasize in our design. Material exposure and iterative testing will always inform the design process. It is up to the designer to inform their decisions with material qualities as well as inform the application of material for its appropriate performance in the design.

FINAL MODEL FABRICATION COMPONENT MACHINING LEFT EACH MODULE INTACT WITH THE FULL SHEET TO CREATE A CONSISTENCY IN THE MACHINING QUALITY AND ALLOW FOR THE QUICK REMOVAL AND LABELING OF EACH CUT SHEET, DIFFICULTIES WERE EXHIBITED IN THE CONNECTION OF THE DOUBLE ARM COMPONENT GEOMETRY. MUCH MORE FORCE WAS NEEDED TO PIN COMPONENTS TOGETHER. THE ULTIMATE PERFORMANCE OF THE ASSEMBLY WAS NOT THE SAME AS THE DIGITAL MODEL.

PORTION OF FINAL MODEL (SHOWN IN TOP RIGHT OF IMAGE) THE MODEL IS PERFORMING APPROPRIATELY WITH EACH COMPONENT TAKING THE CURVATURE. HOWEVER, THE CURVATURE EXHIBITED IS NOT ACCURATE TO THE DIGITAL MODEL

BIBLIOGRAPHY

Books and Articles Jefferson Ellinger, Nona Yehia. “Towards a New Technique.” 2003. Kilian, Axel. “Fabrication of Partially Double Curved Surfaces out of Flat Materials Through a 3d Puzzle Approach.” MIT, Department of Architecture, 2000. Kolarevic, Branko. Architecutre in the Digital Age. UK: Spon Press, 2003. Web Documents Tibbits, Skylar. Live Architecture Network. 2009. http://www.livearchitecture. net (accessed 2008-2009). Zach Downey, Jennifer Downey. Designalyze. 2009. http://www.designalyze. com (accessed 2008-2009).