中厚板铝合金激光-MIG复合焊过程应力与变形研究

The Study of Stress and Deformation During Laser-MIG Hybrid Welding of Medium and Heavy Plate Aluminum Alloy

采用ANSYS对中厚板铝合金的激光-MIG复合焊接过程进行数值模拟,分析激光-MIG复合焊接过程中温度场、残余应力及焊接变形的分布情况。结果发现,由于工件表面与内部的散热速度差异,温度场呈现中间高、周围低、以焊缝为中轴线的椭圆形分布。随着焊接的进行,工件的等效应力在不断增大,焊接过程中工件两侧出现>300 MPa的高应力区;随着工件的冷却,工件两侧刚性固定面的应力集中开始不断消退,且高应力区在工件冷却后消失。工件完全冷却后,高应力区域主要集中分布在焊缝周围,最高值可达175 MPa,工件两侧应力分布较为均匀,在125~130 MPa范围内。焊后工件总变形呈现以焊缝为中轴线的椭圆形分布,焊缝两侧单位变形量最高可达0.19,焊缝部位单位变形量为0.09。

The laser-MIG welding process of medium-thick plate aluminum alloy is simulated by ANSYS, and the distribution of temperature field, residual stress and welding deformation in the laser-MIG composite welding process are obtained. Results show that the temperature field presents an elliptical distribution with the weld as the central axis, and the temperature field is high in the middle and low around the workpiece. Because the equivalent stress of the workpiece is increasing with the welding, during the welding process, a high stress zone of > 300 MPa appears on both sides of the workpiece. With the cooling of the workpiece, the stress concentration of the rigid fixed surface on both sides of the workpiece begins to disappear, and the high stress area disappears after the workpiece is cooled. After the workpiece is completely cooled, the high stress zone is mainly distributed around the welding seam, with the maximum value up to 175 MPa. The stress distribution on both sides of the workpiece is relatively uniform, in the range of 125-130 MPa. After welding, the total deformation of the workpiece presents an elliptical distribution with the weld as the central axis. The maximum deformation on both sides of the weld can reach 0.19, and the weld deformation is 0.09.