A Method of Improving Dynamic Stress Computation for Fatigue Life Prediction of Vehicle Structure

In order to accurately predict fatigue life of vehicle structures or components, it is necessary to predict dynamic stresses efficiently as well as accurately. This paper demonstrates how to improve the accuracy of dynamic stresses that are computed from the conventional flexible multibody dynamic system simulation where modal stress superposition method is used. In the proposed method, the mode-acceleration concept is utilized in each flexible component in the postprocessing stage of dynamic simulation. Numerical examples of a vehicle chassis structure show the effectiveness of the proposed method.