Study on failure assessment and experimental validation of automotive steering knuckle in McPherson front suspension system

Abstract

The failure phenomenon of automotive components within the service life is one of the most concerning issues in the automotive industry. In this paper, the concept of deformation gradient is introduced into the CAE simulation results to obtain the critical strain of the component under large deformation conditions. Subsequently, a complete quasi-static failure prediction method combined with the Johnson-Cook criterion is proposed. In addition, considering the cyclic hardening effect of the components’ material, the subcritical plane model is improved based on the Fatemi-Socie model to make the fatigue life prediction more accurate. According to the assembly relationship of the McPherson front suspension system, the proposed method and the improved model are used to predict the failure of the steering knuckle. Finally, the predicted results are compared with the rig test results. The comparison results validate the applicability and accuracy of the proposed quasi-static failure prediction method and fatigue failure prediction model.