孔挤压强化有限元分析及疲劳寿命估算

摘要

目前孔挤压强化过程仿真方面的文献主要是对于残余应力的分析,疲劳寿命主要由试验测量得到,对疲劳寿命的估算较少.通过三维非线性有限元方法,对7075铝合金芯棒和衬套挤压强化过程进行了仿真.分析了不同强化方法强化后的残余应力分布.在残余应力分析的基础上,估算了循环载荷下不强化、芯棒挤压和衬套挤压强化后元件的疲劳寿命;并与相应的试验数据进行了对比.结果表明,疲劳寿命估算结果与试验结果基本一致,估算方法可行.%The FE model of 7075 aluminum alloy was built based on 3-D nonlinear finite element method,which the mandrel cold expansion and split-sleeve expansion were applied to. The residual stress was calculated and fatigue life was predicted. Experiment was carried out on non-cold expansion, mandrel cold expansion and split-sleeve expansion to obtain the fatigue life improvement. Comparison between the result of experiment and the estimated result shows that they are fitting well, the prediction method is proved feasible.