A Comparative Study on Non-Linear Analysis Using Explicit and Implicit Techniques & Fatigue Life Estimation of Semi-Elliptical Leaf Spring 2018-01-0472

Leaf spring is a vital suspension component, such that the failure of leaf spring could cause fatal accidents. Due to frequent failures of leaf springs on vehicles, a method is developed to perform the numerical analysis using explicit solver which provides insightful analysis of leaf springs to prevent the occurrence of failure during engineering design. Since fatigue life assessment of leaf springs is a significant aspect during the design stage and due to the limitation of non-compatibility of output file of explicit solver for fatigue analysis, various studies are conducted and implicit solver is considered to perform FEA simulation of leaf spring. The present study delineates comparison of non-linear analysis of semi-elliptical leaf spring using explicit solver with that of implicit solver. Analysis using implicit solver gives us an advantage to export the model in fatigue life estimation solver which is not possible using explicit solver. The aim of this study is to establish correlation between FEA simulation (both explicit and implicit methods) and Rig test data for a semi-elliptical suspension leaf spring. This method would then be used to predict durability and other suspension properties like spring rate from the leaf geometry at design stage itself. The stiffness, stresses and load carrying capacity obtained from FEA is compared with that of test rig results keeping the same boundary and loading conditions. Correlations have been achieved in both spring rate (90%) and Stress (95%) at measured strain gauge locations between the Rig test and FEA results. The simulation results indicated that the implicit method is superior to that of explicit method and also helpful for fatigue life estimation of leaf spring. After co-relating the results using both the methods, the life of the leaf spring is determined which is further co-related with test rig results. The Correlation has helped in reducing product design time and cost of running the rig by predicting the behaviour of leaf spring under various loading conditions using finite element analysis.