6061-T651铝合金薄板接头的焊接变形

摘要

Based on the commercial software ABAQUS, a thermo-elastic-plastic finite element method (T-E-P FEM) was developed in consideration of material nonlinearity, geometrical nonlinearity and moving heat source to simulate the thermo-mechanical behavior during welding process. The welding temperature fields, residual stress distribution and deformation in a thin-plate bead-on joint performed by TIG welding process and those in a butt joint with V-groove welded by MIG welding process were simulated. Meanwhile, the transverse shrinkages and out-of-plane deformations in thin-plate welded joints were measured by experiments. The transverse shrinkages and the out-of-deformations simulated by the T-E-P FEM are in good agreement with the measured data, and the effectiveness of the developed computational approach was verified by experiment. In addition, the formation mechanisms of out-of-plane deformation in thin-plate Al alloy joints were clarified based on the numerical and experimental results.%基于有限元软件 ABAQUS，开发可同时考虑材料非线性、几何非线性和移动热源的热−弹−塑性有限元计算方法来模拟焊接过程中的热−力学耦合行为。以3 mm厚的6061-T651铝合金薄板TIG焊单道重熔和MIG对接接头为例，模拟分析焊接过程中的温度场、残余应力和焊接变形。同时，采用实验方法测量两种焊接接头的横向收缩和面外变形。结果表明：数值计算所得到的横向收缩、角变形与实验测量结果十分吻合，验证所开发的有限元计算方法的有效性。此外，基于数值模拟结果和实验结果验证了铝合金薄板焊接接头面外变形的形成机理。