基于固有应变法的中空薄壁铝合金结构件焊接变形及残余应力预测

Welding deformation and residual stress prediction of hollow thin-walled aluminum alloy structural parts based on inherent strain method

为提升中空薄壁铝合金结构件焊接变形与残余应力预测精度。基于固有应变法与焊接热输入参数对焊接等效载荷开展求解,利用有限元仿真方式从变形及应力的角度出发,分别对焊接变形及残余应力进行分析,并通过焊接试验进行验证。结果表明:焊缝左右两侧的边缘区域是产生焊接残余应力的主要位置,横向、纵向残余应力分别为275 MPa、181 MPa,结构件上蒙板呈马鞍形分布,焊接所导致的最大变形分布在上蒙板左右两侧,左右两侧仿真最大值分别0.299 mm、0.274 mm,左右两侧试验最大值分别0.37 mm、0.34 mm,试验变形值略大于仿真变形值,两侧变形预测误差率分别为19.1%、19.4%。研究结果可为类似中空薄壁铝合金结构件焊接变形及残余应力预测提供一定参考依据。

In order to improve the prediction accuracy of welding deformation and residual stress of hollow thin-walled aluminum alloy structures,based on the inherent strain method,the welding equivalent load was solved by using the welding thermal parameters,moreover,from the perspective of deformation and residual stress,the welding deformation and welding residual stress were analyzed by finite element simulation,and then the deformation was verified by welding experiment.The results show that the covering plate on the structural member is saddle shaped,and the maximum deformation caused by welding is distributed on the left and right sides of the upper cover plate,the maximum simulation values on the left and right sides are 0.299 mm and 0.274 mm respectively,and the maximum experiment values on the left and right sides are 0.37 mm and 0.34 mm respectively,and the experiment deformation value is slightly larger than the simulation deformation value,and the prediction error rates of deformation on the left and right sides are 19.1%and 19.4%respectively.The research results can provide a reference for the prediction of welding deformation and residual stress of similar hollow thin-walled aluminum alloy structural parts.