基于MSC.Fatigue的汽车驱动桥壳疲劳寿命预估

运用三维造型软件Pro/Engineer Wildfire2.0建立某型商用车驱动桥后桥壳的实体模型.依据有限元基本理论，进一步建立该桥壳的有限元模型，并在通用有限元分析系统MSC.Nastran中进行有限元应力分析.基于应力分析结果，采用有效的疲劳寿命预估方法，利用专业耐久性疲劳寿命分析系统MSC.Fatigue对该桥壳进行全寿命分析，得到桥壳整体的疲劳寿命分布和危险点的寿命值.通过与台架疲劳试验的桥壳失效情况相对比，预估结果与试验结果一致.而后对在试验中发生破坏的桥壳进行疲劳断口的微观分析.最终在试验与仿真分析结果的基础上提出对该型桥壳生产的改进方案。

Prediction on fatigue life of vehicle's driving axle house based on MSC.Fatigue

The solid model of a commercial vehicle's driving axle house was established with Pro/Engineer Wildfire 2.0.According to FEM theory,the finite element model of this axle house is set up and its stress analysis is performed by FEA software MSC.Nastran.Based on the result of stress analysis,by adopting effective fatigue lifespan prediction method,lifecycle analysis of axle house is conducted by MSC.Fatigue,a professional fatigue analysis system and then fatigue lifespan distribution of the whole axle house body and the lifespan value of most dangerous points are obtained.By comparing the failure position and fatigue life of the axle house in the rig test,the results show that the prediction result is the same as the one obtained from experiments.Then,the fracture surface of specimens which brought on fatigue invalidation in rig test is investigated with scanning electron microscopy(SEM).Finally,on the basis of the results got from simulation calculation and rig test,the modified design of axle house is presented.