TC21钛合金孔挤压强化模拟

Simulation of cold expansion strengthening of TC21 alloy

采用弹塑性有限元法对TC21钛合金耳片衬套挤压和芯棒挤压过程进行仿真模拟,对比分析经两种工艺挤压后孔周边的残余应力分布规律;结合未经孔挤压强化和经两种不同孔挤压工艺强化的耳片疲劳实验结果,对两种不同孔挤压工艺的强化效果进行了分析。结果表明,挤压后孔边残余应力沿径向、周向和厚度方向的分布都呈现一定的变化规律,且芯棒挤压后的残余应力分布比衬套挤压更均匀,两种挤压方式都能起到强化效果,但芯棒挤压的强化效果更好。

Mandrel cold expansion and split‐sleeve expansion of TC21 titanium alloy lugs were simulated by elastic‐plastic finite el‐ement method .Based on the simulation results ,the residual stress distributions around the hole were analyzed .Combining the fa‐tigue experiments of lugs after mandrel cold expansion and split‐sleeve expansion ,the strengthening effects of the two processes were evaluated .Results show that the residual stress distributions along the direction of radial ,circumferential and thickness have some changes .The distribution of the residual stress after mandrel cold expansion is more uniform than that after split‐sleeve ex‐pansion .Both the two kinds of processes can strengthen the holes ,while the effect of mandrel cold expansion is much better .