Experimental Study and Optimization of Leaf Spring N. S. Mendhe a P.G. Student , Govt.College Of Engineering, Osmanpura, Station Road, Aurangabad ( M.S.) INDIA 431005 Dr. S. A. Sonawane b b Assistant professor, Govt.College of Engineering, osmanpura, station road,Aurangabad ( M.S.) INDIA 431005 Prof. K. C. Raipurkar c c Associate professor, MIT(E),Beed Bye pass, Satara Parisar, Aurangabad ( M.S.) INDIA 431005 Abstract - Leaf spring has been a matter of study for many researchers in various areas i.e. static and fatigue characteristics, composite leaf springs, optimization of leaf spring, design of leaf springs for heavy axle loads etc have been studied by researchers. This paper also aims at comparative study of leaf spring by finite element method. Results of both the methods are compared even though composite springs show better results. Attempt has been made to optimize the factors of two different steels. Second method has shown better performance. Keyword: Optimization INTRODUCTION: Leaf spring is a very crucial and important component used in automobile industry. In most cases during truck operation, spring leaves are subjected to five deformation modes such as tension, compression, bending torsion and shear. Therefore, special requirements are imposed on the material and structure of this critical part of the truck chassis. As shown by truck maintenance practices, the material of spring leaves, particularly the main and auxiliary spring leaves, undergoes degradation over a certain time interval, due to which its physical-mechanical characteristics change with the material embrittlement occurring most intensely. This results in the initiation and propagation of fatigue cracks, which under heavy load conditions of truck operation cause early failure of this most critical part of the suspension assembly. [1] Over the last few years the number of applications of composite materials outside the aerospace sector has been steadily increasing in both range and volume. Glass fibre reinforced composite (GFRC) leaf springs for transportation have attracted many researchers.[2] Composite materials are now used extensively in the automotive industry to take the place of metals parts. Several papers were devoted to the application of composite materials for automobiles.[3]Vertical vibrations and impacts are buffered by variations in the spring deflection so that the potential energy is stored in spring as strain energy and then released slowly. So, increasing the energy storage capability of a leaf spring ensures a more compliant suspension system. The amount of elastic energy that can be stored by a leaf spring volume unit [3] is given by Eq. (1) S = σ 2 /2E (1) Where σ is the maximum allowable stress induced into the spring and E is the modulus of elasticity, both in the longitudinal as well as transverse direction. Considering that the dominant loading on leaf spring is vertical force [4], the Eq.(1) shows that a material with maximum strength and minimum modulus of elasticity in the longitudinal direction is the most suitable material for a leaf spring. Fortunately, composites have these characteristics [5].One of the most advantageous reasons for considering composites instead of steel is their weight. Another important characteristics of composites which make them excellent for leaf spring are: higher strength International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 www.ijert.org IJERTV4IS010615 (This work is licensed under a Creative Commons Attribution 4.0 International License.) Vol. 4 Issue 01,January-2015 532