基于变形力数据的结构件残余应力场重构方法

残余应力是引起零件加工变形和失效的重要因素,残余应力场的重构有助于消除和控制零件在设计、制造、评价和使用过程中的残余应力。针对已有方法难以准确重构残余应力场的问题,提出了一种通过零件加工过程中的变形力数据实现零件残余应力场重构的方法。该方法首先提取了由于材料去除引起的应力重新分布带来的装夹力变化数据,即变形力。残余应力到变形力之间通过协方差矩阵自适应进化策略(CMA-ES算法)反复迭代求解出映射关系,从而构建出零件的残余应力场,最后在仿真环境下对该方法进行了验证。验证结果表明:该方法能较好地预测残余应力场,重构出的零件的初始残余应力场与原始施加的应力场平均误差值约0.38 MPa,为零件残余应力场的重构提供了一种新思路。

A Method for Residual Stress Field Reconstruction of Structural Parts Based on Deformation Force Data

Residual stress is an important factor for the deformation and failure of parts. The reconstruction of residual stress field is helpful to eliminate and control the residual stress in the design, manufacture, evaluation, and application of parts. In view of the problem that it is difficult to reconstruct the residual stress field accurately by existing methods, a method for the residual stress field reconstruction of parts is proposed by means of the deformation force data during the manufacturing process of the parts. In this method, the data of clamping force change due to the stress redistribution caused by material removal is extracted firstly, i.e., the deformation force. The mapping relationship of the residual stress and the deformation force of a part is solved by iterations with the covariance matrix adaptation evolution strategy (CMA-ES) algorithm, so that the residual stress field of the part is constructed. Finally, the method is verified in the simulation environment. The results show that the method can well predict the residual stress field, and the average error between the reconstructed initial residual stress field and the original applied stress field is about 0.38 MPa. The method provides a new idea for the residual stress field reconstruction of parts.