TC4管状零件内壁加工残余应力计算及其有限元分析

针对残余应力对加工零件使用性能有严重影响以及TC4材料难以用X射线法进行残余应力测量的现状,提出了一种通过测量外壁应变来计算TC4管状零件内壁加工残余应力的方法。为验证该方法的正确性,在有限元软件中对模型内壁进行分层施加预定的随深度变化的残余应力,并用生死单元技术将内层单元逐层“杀死”来模拟实际实验中应力层被腐蚀的过程。根据外层不断变化的应变以及推导出的计算公式来计算内壁随深度变化的残余应力,并将计算得到的残余应力与之前所施加的应力进行对比,可发现该方法求得的残余应力值准确度较高,由此可以得出结论：该方法可用于测量实际零件的残余应力。

Calculation of Residual Stress Induced by Machining in Internal Surface of TC4 Tubular Parts and Its FEA

With respect to residual stresses had a strong effect on the usability of the parts and the residual stresses in the material of TC4 were hard to measure with XRD method, this paper briefly presented a method to calculate the residual stresses induced by machining in internal surface of TC4 tubular parts. In order to verify the correctness of the method, the residual stresses varying with depth were applied in internal surface of the model in FEA software, the technology of element birth and death was used to “kill” the elements in internal surface layer by layer to simulate the process of corrosion in experiments. And the residual stresses were calculated based on the changing strains on the external surface of the part and the deduced formulas, and then the calculated residual stresses were contrasted to the stresses that were applied to the model.It can be found that the accuracy of the calculated residual stress is very high, so it can be concluded that this method can be applied to measure the residual stress in practice.