Advanced Research Journals of Science and Technology
ADVANCED RESEARCH JOURNALS OF SCIENCE AND TECHNOLOGY
(ARJST)
STATIC AND DYNAMIC ANALYSIS ON COMPOSITE MONO LEAF SPRING
2349-1845
Akkati Ramu 1, Singaiah.Gali 2, 1 Research Scholar, Department of Mechanical Engineering,Hyderabad Institute of Technology And Management,Hyderabad,India. 2 Assistant Professor , Department of Mechanical Engineering, Hyderabad Institute of Technology And Management,Hyderabad,India.
Abstract A leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles. Leaf Springs are long and narrow plates attached to the frame of a trailer that rest above or below the trailer's axle. There are mono leaf springs, or single-leaf springs, that consist of simply one plate of spring steel. These are usually thick in the middle and taper out toward the end, and they don't typically offer too much strength and suspension for towed vehicles. Drivers looking to tow heavier loads typically use multi leaf springs, which consist of several leaf springs of varying length stacked on top of each other. The shorter the leaf spring, the closer to the bottom it will be, giving it the same semielliptical shape a single leaf spring gets from being thicker in the middle. The objective of this paper is to compare the load carrying capacity, stiffness and weight savings of composite leaf spring with that of steel leaf spring. The design constraints are stresses and deflections. The dimensions of an existing conventional steel leaf spring of a Heavy commercial vehicle are taken Same dimensions of conventional leaf spring are used to fabricate a composite mono leaf spring using E-GLASS/EPOXY, C- GLASS/EPOXY, S- GLASS/EPOXY unidirectional laminates. Pro/Engineer software is used for modeling and COSMOS is used for analysis. Static & Dynamic analysis of Leaf spring is performed using COSMOS.
*Corresponding Author:
ABOUT LEAF SPRINGS
Akkati Ramu , Research Scholar, Department Of Mechanical Engineering, Hyderabad Institute of Technology And Management,Hyderabad,India.
Originally called laminated or carriage spring, a leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles. It is also one of the oldest forms of springing, dating back to medieval times.
Published: December 19, 2015 Review Type: peer reviewed Volume: II, Issue : IV Citation: Akkati Ramu ,Research Scholar (2015) STATIC AND DYNAMIC ANALYSIS ON COMPOSITE MONO LEAF SPRING
The advantages of leaf spring over helical spring is that the end of the springs may be guided along a definite path.
INTRODUCTION SUSPENSION Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose – contributing to the car's road holding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations, etc. These goals are generally at odds, so the tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.
TRADITIONAL USE OF LEAF SPRINGS A leaf spring is a long, flat, thin, and flexible piece of spring steel or composite material that resists bending. The basic principles of leaf spring design and assembly are relatively simple, and leafs have been used in various capacities since medieval times. Most heavy duty vehicles today use two sets of leaf springs per solid axle, mounted perpendicularly to support the weight of the vehicle. This Hotchkiss system requires that each leaf set act as both a spring and a horizontally stable link. Because leaf sets lack rigidity, such a dual-role is only suited for applications where load-bearing capability is more important than precision in suspension response. For the purpose of analysis, the leaves are divided into two groups namely master leaf along with graduatedlength leaves forming one group and extra full-length leaves forming the other. The following notations are used in the analysis: nf = number of extra full-length leaves ng =number of graduated-length leaves including master leaf n= total number of leaves b= width of each leaf (mm) t= thickness of each leaf (mm) L=length of the simply supported or half the length of 49
Advanced Research Journals of Science and Technology
semi- elliptic spring (mm) F= force applied at the end of the spring (N) Ff=portion of F taken by the extra full-length leaves (N) Fg=portion of F taken by the graduated-length leaves (N) OVERVIEW OF LEAF SPRING Semi-elliptic leaf springs are almost universally used for suspension in light and heavy commercial vehicles. For cars also, these are widely used in rear suspension. The spring consists of a number of leaves called blades. The blades are varying in length. The blades are us usually given an initial curvature or cambered so that they will tend to straighten under the load. The leaf spring is based upon the theory of a beam of uniform strength. The lengthiest blade has eyes on its ends. This blade is called main or master leaf, the remaining blades are called graduated leaves. All the blades are bound together by means of steel straps.
ceramic as the matrix and reinforce it with short fibres, or whiskers such as those made from silicon carbide and boron nitride. Polymer matrix composites Resin systems such as epoxies and polyesters have limited use for the manufacture of structures on their own, since their mechanical properties are not very high when compared to, for example, most metals. However, they have desirable properties, most notably their ability to be easily formed into complex shapes.
Suspension System The automobile chassis is mounted on the axles, not direct but some form of springs. This is done to isolate the vehicle body from the road shocks, which may be in the form of bounce, pitch, roll or sway. These tendencies give rise to an uncomfortable ride and also cause additional stress in the automobile frame any body. All the part, which performs the function of isolating the automobile from the road shocks, is collectively called a suspension system. It includes the springing device used and various mountings for the same. Broadly speaking, suspension system consists of a spring and a damper. The energy of road shock causes the spring to oscillate. These oscillations are restricted to a reasonable level by the damper which is more commonly called a shock absorber.
Designing with composites There are four main direct loads that any material in a structure has to withstand: tension, compression, shear and flexure. Laminate notation Considering a laminate manufactured using unidirectional (UD) plies, the lay up notation is described as shown below :
Objective of Suspension 1 To prevent the road shocks from being transmitted to the vehicle components. 2. To safeguard the occupants from road shocks 3. To preserve the stability of the vehicle in pitting or rolling, while in motion Basic composite theory In its most basic form a composite material is one, which is composed of at least two elements working together to produce material properties that are different to the properties of those elements on their own. In practice, most composites consist of a bulk material (the ‘matrix’), and a reinforcement of some kind, added primarily to increase the strength and stiffness of the matrix. This reinforcement is usually in fibre form. Today, the most common man-made composites can be divided into three main groups: Polymer Matrix Composites (PMC’s) – These are the most common and will be discussed here. Also known as FRP - Fibre Reinforced Polymers (or Plastics) – these materials use a polymer-based resin as the matrix, and a variety of fibres such as glass, carbon and aramid as the reinforcement. Metal Matrix Composites (MMC’s) - Increasingly found in the automotive industry, these materials use a metal such as aluminium as the matrix, and reinforce it with fibres, or particles, such as silicon carbide. Ceramic Matrix Composites (CMC’s) - Used in very high temperature environments, these materials use a
When designing a laminate it is important to consider the stacking sequence of plies and to be aware of SYMMETRY and BALANCE of the stack. The stack above is both symmetric (about the mid plane) which helps to eliminate any tendency to bend or warp, and balanced meaning that there is an equal number of +45° & -45° plies, which reduces shear coupling. DESIGN OF LEAF SPRING Model:- Ashok Leyland Viking Number of leaf springs =4 Overall length of the spring=2L1=137.2cm=1372mm L1=68.6cm=686mm Width of leaves=76.2 50
Advanced Research Journals of Science and Technology
Number of full length of leaves=2=Nf Number of graduated leaves=12=Ng Number of springs=14=Ng+ Nf Center load=2W=15 tons=15000kg 2W=15000x9.8=147000
Length of leaf spring:
facturing, etc.) typically uses vector-based (linear) environments whereas graphic-based software utilizes rasterbased (pixilated) environments. CADD environments often involve more than just shapes. As in the manual drafting of technical and engineering drawings, the output of CAD must convey information, such as materials, processes, dimensions, and tolerances, according to application-specific conventions. MODELING OF LEAF SPRING
The above image shows master leaf or mono leaf
The above image shows leaf no 11
The above image shows leaf spring assembly view
STRUCTURAL ANALYSIS OF LEAF SPRING MATERIAL: MILD STEEL INTRODUCTION TO CAD Computer-aided design (CAD), also known as computer-aided design and drafting (CADD), is the use of computer technology for the process of design and designdocumentation. Computer Aided Drafting describes the process of drafting with a computer. CADD software, or environments, provides the user with input-tools for the purpose of streamlining design processes; drafting, documentation, and manufacturing processes. CADD output is often in the form of electronic files for print or machining operations. The development of CADD-based software is in direct correlation with the processes it seeks to economize; industry-based software (construction, manu-
The above image shows meshed model
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Advanced Research Journals of Science and Technology
The above image shows load applied The above image shows stress
MATERIAL: C-GLASS EPOXY
The above image shows displacement
The above image shows displacement
The above image shows stress
The above image shows stress
MATERIAL: E-glass epoxy
The above image shows strain
MATERIAL: S2-glass epoxy
The above image shows displacement
The above image shows displacement
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Advanced Research Journals of Science and Technology
HARMONIC ANALYSIS OF LEAF SPRING MATERIAL: MILD STEEL
The above image shows stress
The above image shows displacement
FREQUENCY ANALYSIS OF LEAF SPRING MATERIAL: MILD STEEL
The above image shows stress
The above image shows total deformation mode
MATERIAL: S2-glass epoxy
STRUCTURAL ANALYSIS ON MONO LEAF USING CGLASS COMPOSITES WITH 450 00 450
The above image shows total deformation mode
MATERIAL: C-glass epoxy The above image shows imported model
The above image shows total deformation mode
MATERIAL: E-GLASS EPOXY
The above image shows layer orientation
The above image shows total deformation mode
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Advanced Research Journals of Science and Technology
The above image shows stress
LEAF STATIC ANALYSIS The above image shows total deformation Stress
Displacement
Strain
MILD STEEL
55.2891
0.0722747
0.000162503
S-GLASS
53.2077
0.17071
0.000340289
C-GLASS
52.4395
2.15245
0.00445177
E-GLASS
53.4535
0.204899
0.000402899
HARMONIC ANALYSIS
The above image shows stress
STRUCTURAL ANALYSIS ON MONO LEAF USING CGLASS COMPOSITES WITH 900 00 900
Stress
Displacement
MILD STEEL
48.8402
0.0634696
S-GLASS
49.4931
0.150244
C-GLASS
49.8046
0.180383
E-GLASS
53.5033
2.08616
Layer orientation 450 00 450 C-GLASS
E-GLASS
S2-GLASS
Total deformation
.898e-3
0.854e-3
0.712e-3
Stress
.338762
.334201
0.335498
Strain
0.492e-6
0.462e-6
0.386e-6
E-GLASS
53.4535
0.204899
0.000402899
Layer orientation 900 00 900
The above image shows layer orientation
C-GLASS
E-GLASS
S2-GLASS
Total deformation
.925934
.883241
0.007117
Stress
18.8945
18.8283
3.35498
Strain
.274e-4
0.260e-4
0.386e-6
E-GLASS
53.4535
0.204899
0.000402899
CONCLUSION This project work is done on “STATIC AND DYNAMIC ANALYSIS ON COMPOSITE MONO LEAF SPRING” to give clear description and suggestions about composite materials. In the stage one lituracher survey is done on leaf springs to understand calculations and material selection, Data collection is done to understand FEM approach, composite materials for suspension system and importance of software application.
The above image shows total deformation
In the next stage mathematical calculations are done to determine leaf spring part & assembly diminutions, from the calculations results a 3d model is prepared and exported into IGES ”Initial Graphical Exchange Specifica54
Advanced Research Journals of Science and Technology
tions” to do further FEM study. In the next stage structural analysis is done on part to evaluate deformation, stress and strain results for the three composite materials C-GLASS, E-GLASS, & S2GLASS, Dynamic Analysis is conducted to evaluate harmonic frequency values which is caused by the external vibrations. In the next stage above analysis work is done with the variation of material matrix angles “re-enforcement angles” 450 00 450 & 900 00 900 as per ASME 2014 standards we need to take 0/45/-45/900 only. As per the results obtained for the above analyses this project work concludes that. S2-glass epoxy “carbon reenforced fiber polymer laminates” with 900 00 900 angle will be the best option for making leaf spring manufacturing than other composites and traditional material Mild Steel while comparing with stress, factor of safety, and weight factors.
Author
Akkati Ramu , Research Scholar, Department of Mechanical Engineering, Hyderabad Institute of Technology And Management, Hyderabad,India.
REFERENCES 1. Modeling and Analysis of Laminated Composite Leaf Spring under the Static Load Condition by using FEA, International Journal of Modern Engineering Research (IJMER) 2. DESIGN AND ANALYSIS OF COMPOSITE LEAF SPRING FOR LIGHT VEHICLES
Singaiah.Gali, Assistant professor , Department of Mechanical Engineering, Hyderabad Institute of Technology And Management, Hyderabad,India.
3. Design & Analysis of Mono Composite Leaf Spring, International Journal of Scientific Research Engineering & Technology (IJSRET) 4. A Comparative Study of CAE and Experimental Results of Leaf Springs in Automotive Vehicles, International Journal of Engineering Science and Technology (IJEST) 5. Performance Analysis of Two Mono Leaf Spring Used For Maruti 800 Vehicle, International Journal of Innovative Technology and Exploring Engineering (IJITEE) 6. Stress Analysis of a Mono-parabolic Leaf Spring–A Review, International Journal of Modern Engineering Research (IJMER) 7. Modelling and Analysis of Suspension System of TATA SUMO by using Composite Material under the Static Load Condition by using FEA, International Journal of Engineering and Advanced Technology (IJEAT) 8. Design Optimization Of Leaf Spring, International Journal of Engineering Research and Applications (IJERA) 9. PERFORMANCE ANALYSIS OF STEEL LEAF SPRING WITH COMPOSITE LEAF SPRING AND FABRICATION OF COMPOSITE LEAF SPRING. 10. Design and Structural Analysis of Jute/E-glass Woven Fiber Reinforced Epoxy Based Hybrid Composite Leaf Spring under Static Loading, International Journal of Mechanical Engineering and Research. 11. ANALYSIS OF COMPOSITE LEAF SPRING USING FEA FOR LIGHT VEHICLE MINI TRUCK, Journal of information, knowledge and research in mechanical engineering
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