中文摘要：

矿用自卸车行驶路况非常恶劣，为研究国产首台SF33900型矿用白卸车后桥壳的疲劳寿命，建立后桥壳有限元分析模型，将载荷峰值作用下的仿真应力结果与试验结果进行对比分析，得出两者数值比较接近，从而验证了该模型具有一定的准确性。将动力学分析结果作为后桥壳疲劳寿命分析的随机载荷谱，得出水平路面普通工况下的疲劳寿命分布云图，其最小寿命满足工程要求。为研究载荷变化对后桥壳疲劳寿命的灵敏性，对比分析三处载荷变化对后桥壳疲劳寿命的影响程度，得出后横拉杆和悬架下支点位置受力变化对后桥壳疲劳寿命影响较大。另外，还考虑载荷频率变化对后桥壳疲劳寿命的影响，结果表明，载荷频率变化比幅值变化更能影响疲劳寿命。

英文摘要：

In order to study fatigue life of rear axle housing of the first Chinese SF33900 mining dump truck, the t＇mite element model of rear axle housing is built. Stress analysis and experimental results are compared, which finds out that the margin of error is acceptable and verifies the accuracy of the model as well. Regarding dynamics analysis results as random load of fatigue life analysis of rear axle housing, fatigue life contours are obtained under normal conditions and the minimum life meets the engineering requirement. For the purpose of studying the sensitivity between load change and fatigue life, the impact of fatigue life under amplitude changes of the three loads is contrastively analyzed, which gets that the load of rear tie rod and suspension have greater impact on fatigue life of rear axle housing. Otherwise, the change of load frequency also plays a great role in fatigue life. The results show that the chanlze of load frequency has a greater influence on fatigue life of rear axle housing than the change of load amplitude.