残余应力重分布引起的薄壁零件加工变形研究

现代航空工业中为减轻飞机重量，提高飞机的各项机械性能，整体构件越来越多地被使用。加工大型整体薄壁构件时，有90％以上的材料被切削加工去除，由于材料去除后零件刚度的降低以及应力的释放，造成过大的加工变形。本文用MSC．Marc有限元软件仿真了铝合金预拉伸板材料去除对于加工变形的影响，并分析了加工变形的成因。为验证有限元结果的正确性，在高速数控铣床上加工了同样的试件。结果表明仿真结果与实验结果一致，残余应力的释放与重分布是薄壁零件加工变形的主要原因。

Study on the Machining Distortion of Thin-walled Part Caused by Redistribution of Residual Stress

In order to reduce the weight of airplane and increase its mechanical behaviors, more and more large integrated parts are applied in modern aviation industry. When machining thin-walled aeroplane parts, more than 90% of the materials would be removed, resulting in severe distortion of the parts due to the weakened rigidity and the release of residual stress. This might also lead to stress concentration and damage of the parts. The effect of material removal from residually stressed billet is simulated using FEA software MSC. Marc and the causations of distortion is analyzed. To verify the finite element simulation, a high speed milling test on aluminum alloy 7050T7351 is carried out. The results show that the simulation result is consistent with the experimental one. It is concluded that the release of residual stress is the main cause of machining distortion.