基于形状改变比能和材料属性离散的焊接残余应力估算

为了提高焊接残余应力测量精度,在2219-T87铝合金TIG焊接接头残余应力测定试验基础上,通过离散接头材料属性并利用形状改变比能对焊接残余应力进行塑性修正,分别研究孔边塑性变形和接头强度不匹配对焊接残余应力估算的影响。结果表明：同时考虑孔边塑性变形和接头强度不匹配因素的焊接残余应力估算方法,比线弹性残余应力计算方法能最大减小39.8%的误差;当测量点距焊缝距离小于8mm时,在考虑孔边塑性变形的情况下,同时考虑接头不匹配的影响相比不考虑其影响可最大减小40.6%的误差;当测量点距焊缝距离大于8mm时,可忽略接头强度不匹配对焊接残余应力估算的影响。

Welding Residual Stress Estimation based on the Shape-changed Strength Ratio and Material Property Discretization

In order to improve the measurement accuracy of welding residual stress, welding residual stress is corrected by using shape-changed strength ratio and the method of discretizing joint material property on the base of residual stress test of 2219-T87 aluminum alloy TIG welding joint. Simultaneously, the effects of plastic deformation around holes and joint strength mismatch on welding residual stress estimation are studied separately. The results show that the method of estimating welding residual stress which considers both plastic deformation around hole and joint strength mismatch can reduce 39.8% error through contrasting with linear elastic estimation method; The way of considering the effect of joint strength mismatch and plastic deformation can reduce 40.6% error when the distance between the measuring point and welding seam is less than 8mm; And the joint strength mismatch effect on welding residual stress estimation can be ignored when the distance between the measuring point and welding seam is more than 8mm.