基于固有应变法的激光复合焊车体侧墙焊接变形数值模拟

Numerical simulation on laser hybrid welding deformation of side walls of train body based on inherent strain method

基于固有应变法,采用3D高斯+双椭球热源模型预测某高速列车8 m侧墙部件在不同焊接顺序和不同约束方式下激光复合焊的焊接变形。结果表明,该侧墙部件厚度方向变形受焊接顺序影响较大,优化焊接顺序可将侧墙厚度方向的变形降低约13%。焊接约束条件对侧墙部件弧面轮廓度及弧面弦长宽度影响较明显,对整体长度变化影响不大。该侧墙部件焊接首尾两端及中间部分实施合理约束可有效控制变形,相比于无约束,厚度方向最大变形降至25%,宽度方向最大变形降低至10%。经模拟结果与试验实测对比可知,该侧墙部件在其工艺条件下的热源模型选取有效、合理,测量点数值模拟与实际试验吻合较好,绝对误差小于1 mm。

Based on inherent strain method,3 D Gaussian+double ellipsoid heat source model was used to predict laser hybrid welding deformation of 8 m side wall components of a high-speed train under different welding sequence and constraint modes.The results showed that deformation in the thickness direction of side walls was greatly affected by welding sequence,and it could be reduced by about 13%after optimizing the welding sequence.The welding constraints had obvious influence on the arc profile and arc chord width of the side wall components,but had little influence on the overall length.Compared with unconstrained condition,the maximum deformation in the thickness direction was reduced to 25%,and the maximum deformation in the width direction was reduced to 10%.The comparison between simulation results and test results showed that the heat source model selection of the side wall component under its process conditions was effective and reasonable,and the numerical simulation of the measurement points was in good agreement with the actual tests,with the absolute error less than 1 mm.