关键词: 转向节, 减振器阻尼系数, 虚拟迭代, 疲劳寿命, 模态应力恢复

Abstract: In order to study the influences of shock absorber damping coefficients on fatigue life of steering knuckles, taking a compact SUV(sport utility vehicle) as the research object, through modal analysis and testing of steering knuckles, the flexible body models and the fatigue simulation analysis models of steering knuckle were established. The rigid-flexible coupling multi-body dynamics models of the whole vehicle were established based on the parameters of the real vehicles, and based on the six-component forces of the wheel center and the strain signals of the steering knuckle monitoring points collected by the real vehicles in the testing proving ground, using virtual iteration method simulation the load time history(modal displacement) of steering knuckles was obtained. The fatigue life of steering knuckles in different shock absorber damping coefficients was analyzed by using modal stress recovery method, and the relationship between both of them was discussed. The results show that the fatigue life of steering knuckles increases first and then decreases with the increase of damping coefficients in the range considering both of comfort and safety of the whole vehicle, that is, the damage areas of the main area affecting the fatigue life of steering knuckles decreases first and then increases. The damage areas of the secondary area which affects the fatigue life of steering knuckles always increases with the increase of damping coefficients.

Key words: steering knuckle, shock absorber damping coefficient, virtual iteration, fatigue life, modal stress recovery