Design and Experimental Analysis of Leaf Spring Using Composite Materials

Design and Experimental Analysis of Leaf Spring Using Composite Materials

E. Janarthan1 M. Venkatesan2

# PG scholar, Computer aided design,University college of engineering,Nagercoil.

* Assistant Professor,.Department of mechanical Engineering,University college of Engineering,Nagercoil

ABSTRACT-

The objective of this present work is to estimate the deflection, stress and mode frequency induced in the leaf spring of a sumo design by the ordinance factory. The emphasis in this project is on the experimental and computer aided analysis using finite element concept. The component chosen for analysis is a leaf spring which is an automotive component used to absorb vibrations induced during the motion of vehicle. It also acts as a structure to support vertical loading due to the weight of the vehicle and payload. Under operating conditions, the behaviour of the leaf spring s complicated due to its clamping effects and interleaf contact, hence its analysis s essential to predict the displacement, mode frequency and stresses. The leaf spring, which we are analyzing, is a specially designed leaf spring used in sumo. A model of such sumo has been shown in this project report. In analysis part the finite element of leaf spring is created using solid tetrahedron elements, appropriate boundary conditions are applied, material properties are given and loads are applied as per its design, the resultant deformation, mode frequencies and stresses obtained are reported and discussed. There are 3 different sample 40% epoxy-60% E-fiberglass and 60% epoxy – 40% E- fiberglass, 70% epoxy – 30% E- fiberglass

INTRODUCTION

Several papers have been published denoting the application of composites in leaf spring. Other conventional suspension systems work on the same principles as a conventional leaf spring. However leaf springs use excess material when compared to other suspension systems for the same load and shock absorbing performance which makes it heavy. This can be improved by composite leaf springs Considering the fact that the conventional leaf spring is one of the potential components for weight reduction it has been an area of interest for automobile industries The various advantages possessed by the composite materials make this an attractive alternative material for the designers. In an experimental investigation comparison between

the single leaf spring of variable thickness composite spring of fibre glass reinforced fibre with mechanical and dimensional properties similar to the conventional steel leaf spring wasdone by Al-Qureshiet al with

mechanical and dimensional properties similar to the conventional steel leaf spring was done.

MATERIAL PRPPERTIES OF E GLASS /EPOXY

COMPOSITE MONO LEAF SPRING

Camber = 78mm Span = 900mm Thickness = 11mm Width = 107mm

FABRICATION OF COMPOSITE SAMPLES

Layup Selection

The amount of elastic energy that can be stored by a leaf spring varies directly with the square of maximum allowable stress and inversely with the

modulus of elasticity both in the longitudinal direction. Composite materials like the E-Glass/ Epoxy in the direction of fibres have good characteristics for storing strain energy. So, the layup is selected to beunidirectional along the longitudinal direction of the spring. The unidirectional layup weaken the spring at the mechanical joint area and require strengthening the spring in thisregion.DiGlycidyl Ether of Bisphenol A was used as epoxy resin and Tri-Ethylene Tetra-Amine was used as hardener. E-Glass fibres were used as reinforcements.

HAND LAYOUT MOULDING

Hand lay-up moulding is the method of laying down fabrics made of reinforcement and painting with the matrix resin layer by layer until the desired thickness is obtained. This is the most time and labour consuming composite processing method, but majority of aerospace composite products are made by this method in combination with the autoclave method. Due to the hand assembly involved in the lay-up procedure, one can align long fibres with controlled directional quality. Another advantage of this method is the ability to accommodate irregular- shaped products. Such advantages are utilized in low performance composites including fibre – glass boat and bath tub manufacturing. An easy way to comply with the conference paper formatting requirements is to use this document as a template and simply type your text into it. Hand lay technique was used to manufacture the fibre glass reinforced specimen. For this an E – fibreglass material was used with the diameter of the fibreglass approximately epoxy (DiGlycidyl Ether of Bisphenol A) and a hardener (Tri-ethylene Tetra-amine).

Three samples of the fibre glass reinforced plastic were prepared:

1. 40%-60%:-40% epoxy and 60% E-fibreglass

2. 60%-40%:-60% epoxy and 40% E-fibreglass

3. 70%-30%:-70% epoxy and 30% E-fibreglass

SAMPLE

1. 60% eglass & 40% Epoxy

2. 40% eglass & 60% Epoxy

3. 30% eglass & 70% Epoxy

   EXPERIMENTAL WORK

   TESTING OF MECHANICALPROPERTIES

   Tensile test

   The tensile test was carried out using an universal testing machine. The test specimen is prepared according to ASTM D standard. The tensile strength is calculated according to the following formula

   t =P / bh

   Flexural test

   The flexural test is carried out using the universal testing machine. The test specimen was prepared according to ASTM D standard. The flexural strength

   is calculated according to the following formula Flexural strength: f =3PL/2bp

   Hardness test

   The test was conducted using Rockwell L- scale, which is especially for plastic materials, Bakelite and vulcanized rubber. The indenter chosen is of diamond. A load of 60 kg was used for the test.

   Sl.no	parameter	60% and 40%	40% and 60%	70% and 30%
   1.	Fmax	6500	5280	3250
   2.	Tensile strength	107 Mpa	92.2Mpa	46 Mpa

   Sl.no	parameter	60% and 40%	40% and 60%	70% and 30%
   1.	Fmax	6500	5280	3250
   2.	Tensile strength	107 Mpa	92.2Mpa	46 Mpa

   RESULT OF EXPERIMENTAL WORK TENSILE TEST

   Flexural test

   Sl.no	parameter	SPECIMEN I 60% and 40%(EXP)	60% and 40% (FEA)
   1.	Fmax	1000	1000
   2.	Bending stress	442	341
   3.	displacement	7.5	10.21

   Sl.no	parameter	SPECIMEN I 60% and 40%(EXP)	60% and 40% (FEA)
   1.	Fmax	1000	1000
   2.	Bending stress	442	341
   3.	displacement	7.5	10.21

   1.

   2.

   Sl.no	parameter	SPECIMEN II 40% and 60%(EXP)	40% and 60% (FEA)
   1.	Fmax	800	800
   2.	Bending stress	330	237
   3.	displacement	7	6.85

   3.

   Sl.no	parameter	SPECIMEN III 30% and 70%(EXP)	30% and 70% (FEA)
   1.	Fmax	800	800
   2.	Bending stress	330	213
   3.	displacement	6.3	5.95

   HARDNESS TEST

   Sl.no	SPECIMEN I 60% and 40%	SPECIMEN II 40% and 60%	SPECIMEN III 30% and 70%
   1.	5	4	3
   2.	4	3	3
   3.	5	3	4

   DYNAMIC ANALYSIS

   The analysis of a structural system as a function of displacement under transient loading conditions

   MODAL ANALYSIS

   Modal analysis is the study of the dynamic properties of structure under vibration excitation.

   The modal analysis are carried out to determine the natural frequency and modal shape of the leaf spring Experimental analysis

   Sl.no	60% and 40%	40% and 60%	30% and 70%
   1.	34	35	39
   2.	234	242	263
   3.	543	600	694

   FEA Analysis

   Sl.no	60% and 40%	40% and 60%	30% and 70%
   1.	54	68	71
   2.	342	413	381
   3.	405	428	447

   MODAL ANALYSIS

   Different mode shape condition of various Composition

   STRESS ANALYSIS

   500

   400

   stress

   stress

   300

   200

   100

   0

   FEA ANALYSIS

   200 400 600 800 1000

   load

   composition 1

   composition 2

   composition 3

   FEA ANALYSIS

   12

   10

   displacement

   displacement

   8

   6 composition 1

   4 composition2

   composition3

   2

   RESULTS AND DISCUSSION

   0

   200 400 600 800 1000

   load

   Experimental work

   9

   8

   displacement

   displacement

   7

   6

   5

   4

   3

   2

   1

   0

   200 400 600 800 1000

   load

   composition 1 composition2

   composition3

   CONCLUSION

   Thus we compare the composite material Eglass /epoxy various composition. Which one the best composition of experimental work and analysis for various mechanical test and vibration test .

   1. Eglass 60% and 40% epoxy

   2. Eglass 40% and 60% epoxy

   3. Eglass 30% and 70% epoxy

110

100

90

Tensile stress

Tensile stress

80

70

60

50

40

Experimental work

composition1 composition2

E glass 60% and 40% epoxy is the best of tensile and bending stress, deformation, and natural frequency compare the other composition. The natural frequencies of various parametric combinations are compared with the excitation frequency for different road irregularities. The strength to weight ratio is higher for composite leaf spring than conventional steel spring with similar design.

30 composition3

20

10

0

500 1500 2500 3500 4500 5500 6500

load

REFERENCES

1. Dharam, C. K. Composite Materials Design and Processes for Automotive Applications. The ASME Winter Annual Meeting, San Francisco, 1978.

2. Springer, George S., Kollar, Laszloa P. Mechanics of Composite Structures. Cambridge University Press, New York, 2003.

3. AL-Qureshi, H. A. Automobile leaf springs from composite materials, Journal of Processing Technol., 2001

4. Breadmore, P., Johnson, C.F., 1986. The potential for composites in structural

   Automotive applications. Composites Science and Technology, 26(4): 251-81.

5. Kueh, J.J., Faris, T., 2011. Finite element analysis on the static and fatigue characteristics of composite multi-leaf spring. Journal of Zhejiang University- Science A(Applied Physics & Engineering) 2011.

6. Lukin, P., Gasparyants, G., Rodionov, V., 1989. Automobile Chassis-Deign and

   Calculations Moscow: MIR Publishers.

7. Al-Qureshi, H.A., 2001. Automobile Leaf Springs from Composite Materials. Journal of Materials Processing Technology 118(2001):58-61.

8. Shokrieh, M.M., Rezaei, D., 2003. Analysis and Optimization of a Composite LeafSpring. Composite Structures 60 (2003): 317-325