Fatigue Life Prediction Methodology for Vehicle Suspension System and correlation with Physical Test

Fatigue Analysis is a safety critical area in design engineering for load bearing members. The design of a durable suspension system forms the foundation of vehicle architecture. The challenge lies in accurately predicting fatigue in critical areas to reduce field failures, primarily due to the absence of a validated methodology for fatigue calculation. This study provides an overview of fatigue assessment for Knuckle assembly/Rear Twist Beam based on digital Road Load/test Data for Finite Element Analysis (FEA) process for design development. This study makes use of Computer Aided Engineering (CAE) solvers such as Optistruct for model setup and fatigue tool such as nCode/FEMFAT for Fatigue Analysis. The methodology used for Fatigue estimation of rear suspension components such as Rear Twist Beam and Knuckle assembly is based on Digital Road Load Data/duty cycle loads applied to the suspension components at the hard point location at assembly level. The fatigue process used for assessment of rear suspension components has been validated with benchmarked data for increasing accuracy of results. The application of accurate Finite Element Analysis (FEA) to the rear suspension reduces field failures in addition to cost saving due to reduction in physical tests during the vehicle development cycle. As a result of reduced physical tests, manufacturing feasibility is developed with a better confidence at concept level during the development cycle.