Systematic Work Flow for Fatigue Life Prediction of Automotive Components

Fatigue life estimation of automotive components is a critical requirement for product design and development. Automotive companies are under tremendous pressure to launch new vehicles within short duration because of customer’s changing preferences. There is a necessity to have a comprehensive virtual simulation and robust validation process to evaluate durability of vehicle as per customer usage. Test track and field test are two of the most time-consuming activities, so there is a need of simulation process to substitute these requirements. This paper summarizes the overall process of Accelerated Durability Test with measured road loads. Based on category of vehicle, type road profiles and the customer usage pattern, the wheel forces, strains and acceleration are measured which is used to derive the equivalent duty cycles on proving ground. The wheel force transducers (WFT) are used to derive loads for fatigue life estimation. A full vehicle model is prepared in ADAMS CAR and validated through Physical testing. The loads on suspension hard points extracted from the validated MBD model. These loads at various hardpoint locations, are used to carry out the fatigue life calculation. The study provides early design insights and flexibility to incorporate design changes required to meet the acceptable criteria in the initial phase of product development.