基于ABAQUS软件建立了考虑搭接界面接触约束的顺序耦合热-弹塑性有限元模型,研究了完全熔透和部分熔透搭接激光焊接接头的温度场、残余应力场以及焊接变形,并通过试验验证了模型的准确性。结果表明:完全熔透焊接接头由于热输入量较高,其高纵向残余应力区的范围比部分熔透焊接接头宽约30%;由于部分熔透板材对焊缝金属自由膨胀的约束强于熔透板材,故部分熔透焊接接头下板搭接界面的横向残余应力峰值(198 MPa)大于完全熔透焊接接头;部分熔透焊接接头上下表面之间的横向收缩差异明显大于完全熔透焊接接头,从而导致部分熔透焊接接头沿板厚方向的焊接变形更大。

In this study, a sequentially coupled thermal-elastoplastic finite element model considering the contact constraints of lap interface is developed to investigate temperature field, residual stress field, and welding deformation of full and partial penetration laser welded lap joints based on ABAQUS software, and the accuracy of numerical results is verified through experimental results. Results show that the high-stress zone of the full penetration welded joint is 30% wider than that of the partial penetration welded joint because the heat input of the former is relatively higher. The transverse residual stress on lower plate lap interface of the partial penetration welded joint is 198 MPa and higher than that of full penetration welded joint because the free expansion constraint of the weld metal in partial penetration plate is stronger than that in the full penetration plate. The difference of transverse deformation between the upper plate surface and the lower plate surface of the partial penetration welded joint is significantly larger than that of the full penetration welded joint, which causes the deformation in the thickness direction of the former to be larger than that of the latter.