薄板T型接头双丝MAG焊接残余应力及变形有限元分析

Finite element analysis of residual stress and deformation in twin wire MAG welding of thin pate T-joint

采用ABAQUS模拟并分析6 mm厚T型接头双丝MAG焊的焊接温度场、焊后残余应力、焊接面外变形。约束条件分为两种:方案一,不对底板进行固定,焊接自由变形;方案二,焊接时对底板进行固定,冷却后解除固定。结果显示:在相同的热源下,两种方案的焊接温度场保持一致;方案一的角变形量较大,最大变形量约为1 mm,焊缝热影响区底板变形量约为0.2 mm,最大残余应力位于焊缝中心,约235 MPa;方案二的最大变形处位于焊缝中心,但面积较小,可忽略不计,故最大变形量位于底板焊缝热影响区附近,约0.3 mm,焊缝中心的最大残余应力约为180 MPa。由此可见,在T型接头焊接时,将底板进行固定,冷却后解除释放,可以降低焊接残余应力和焊接面外变形量。

In this experiment, ABAQUS was used to simulate and analyze the welding temperature field, post welding residual stress and out of plane deformation of 6 mm thick T-joint double wire MAG welding. There are two kinds of constraint conditions: scheme 1 does not fix the bottom plate and the welding is free from deformation;scheme 2 fixes the bottom plate during welding and releases the fixation after cooling. The results show that the welding temperature fields of the two schemes are consistent under the same heat source;the angular deformation of scheme 1 is large, the maximum deformation is about 1 mm, the deformation of the bottom plate in the weld heat affected zone is about 0.2 mm, and the maximum residual stress is located in the weld center, about 235 MPa;the maximum deformation in scheme 2 is located in the weld center, but the area is small, the maximum deformation is located near the weld heat affected zone, about 0.3 mm, and the maximum residual stress in the weld center is about 180 MPa;The analysis shows that the welding residual stress and out of plane deformation can be reduced by fixing the base plate and releasing it after cooling.