멀티링크 토숀빔 후륜 현가장치의 피로 수명 평가

This study investigated the durability analysis of a multi-link torsion beam rear suspension for a front drive vehicle. The strain-life curve of a hot-rolled plate APFH540P was experimentally obtained using the low-cycle fatigue test procedure of ASTM. To validate the finite element model of the rear suspension system, the result of the model's prediction was compared with those of the photoelastic and the strain gauge measurements in each direction of static loads; longitudinal, lateral, and vertical. Also, the fatigue life of the system was evaluated through bench tests and the model predictions. To evaluate the severity of load conditions in the bench test, input loads of the rear suspension system were collected for a full car in the durability proving ground. Based on these data, uni- and multi-axial fatigue lives of the model were estimated and then compared with those of the bench test. In addition, the sensitivity analysis for the spring coefficient of the shock absorber assembly was studied to prove reliability of the model's prediction.