Stress, Deformation and Failure Analysis of Parabolic Leaf Spring by Finite Element Analysis with Material Optimization

A leaf spring is a simple form of spring commonly used for the suspension system in heavy duty vehicles which is originally called laminated or carriage spring. It performs the isolation task in transferring the vibration due to road irregularities to the passenger's body or goods transported on it. The advantage of leaf spring over helical spring is that the ends of the spring have been guided along a definite path as it deflect to act as a structural member in addition to an energy absorbing device. Increasing competition and innovations in the automobile sector, tends to modify the existing products with new or advanced material products. To improve the performance of the suspension system, many modifications have been taken place overtime but the recent innovations imply parabolic leaf spring and application of composite materials, as the composite materials have high strength-to-weight ratio compared to the conventional steels. The present work attempts to analyze the comparison between the conventional steel (AISI1030) leaf spring and the composite (Carbon/Epoxy) leaf spring with respect to static and fatigue analysis. Here static analysis determines the safe stress, deformation and corresponding pay load and also studies the behavior of structures under practical conditions. The research also focuses on fatigue analysis to determine its life cycle and also to observe its fatigue failure characteristics. The model of the leaf spring has been carried out into the CAD software. The analysis of the steel leaf spring has been divided into theoretical, experimental and simulation sections. The simulation of steel leaf spring has been validated with the theoretical and the experimental results. Further simulation has been done for composite leaf spring by FEA software. Finally, the result shows that the composite leaf spring has better load carrying capacity in reduced weight, and better fatigue behavior rather than the conventional steel material for the leaf spring.