考虑塑性和刚度不匹配的焊接残余应力估算

现有残余应力计算方法未能考虑材料塑性变形和焊接接头刚度不匹配的影响,使得焊接残余应力计算结果和实际残余应力存在较大偏差.在2219-T87铝合金钨极氩弧焊焊接头残余应力测试基础上,提出一种基于非线性有限元和材料弹性模量分区的残余应力—释放应变曲线的残余应力计算方法,研究了材料塑性变形和接头刚度不匹配对焊接残余应力计算的影响.结果表明,焊接接头中非均质材料塑性不匹配可以引起对于残余应力计算的较大误差；材料塑性变形对残余应力的影响大于接头刚度不匹配对残余应力的影响.所提出方法修正了传统方法在焊接接头的残余应力计算中由于未考虑接头非均质材料塑性不匹配而引起的误差.

Estimation of Welding Residual Stress by Taking into Account the Mismatch of Material Plasticity and Joint Stiffness

In existing residual stress calculation, there is a big deviation between the calculation results and actual residual stress of welding residual stress, due to not taking into account the effects of material plastic deformation and welded joint stiffness mismatch. Based on residual stress test of 2219-T87 TIG welded joints, a residual stress calculation method is put forward in this paper to study the effect of material plastic deformation and joint stiffness mismatch on the welding residual stress by using nonlinear finite element and the residual stress-release strain curve in material elastic modulus partition. Results show that the mismatch of non-homogeneous material plasticity in welded joints may cause large error in residual stress calculation, and the impact of the residual stress of plastic deformation is greater than that of the joint stiffness mismatch. The proposed method may modify the error due to taking into account the mismatch of non-homogeneous material plasticity in welded joints.