超载拉伸消除焊接残余应力的计算机模拟

Computer Simulation of Removing Welding Residual Stress by Over Load Tension

焊接件内部总是存在着较大的残余应力，对焊接件的承载能力和抗腐蚀性能有很大影响，本文采用弹塑性有限元方法对超载拉伸消除焊接残余应力过程进行了数值模拟．对三种拉伸载荷下的宽板和窄板两种模型进行的模拟结果表明：拉伸载荷越大，残余应力消除得越好，但是也不能通过一味地增大拉伸载荷来得到较好的残余应力消除效果，而必须同时考虑材料的塑性储备、构件允许的变形量及构件允许的残余应力等，以防过量变形使构件脆断的危险性增大．

There is always high residual stress in weldments. It reduces greatly the load supporting capacity and corrosion resistance of the weldments. The stress fields in a wide plate and a narrow plate under three loads are calculated by elastic plastic finite element method. It is shown that the greater the tension load, the better the result of removing residual stress. However, great deformation will make the weldments brittle. Therefore, the plasticity and allowable deformation of the weldments as well as the result of removing residual stress should be considered when the tension load is determined.