Analysis of surface failure of coil spring in passenger vehicle suspension system

Abstract

This study aims to investigate the failure of a coil spring. The examination of the chemical composition, hardness testing and observation of the fracture surface were performed, and the shear stress occurring on the coil spring was calculated. The results indicated that the inner side of the coil spring was harder than the outer side. Furthermore, the failure was fatigue failure; as shown by the presence of the crack initiation and the benchmarks. The crack initiation occurred because of the stress concentration at one point due to fretting.