铝合金薄板焊件纵向塑性应变场的数值模拟

利用弹塑性有限元分析软件对普通焊件的纵向塑性应变场进行了模拟.结果表明,对于尺寸为200 mm×100 mm ×2 mm的2A12T4铝合金薄板填丝对接焊件,其焊缝部位只存在纵向拉伸塑性应变；在靠近焊缝的区域,既存在纵向压缩塑性应变,也存在纵向拉伸塑性应变；在焊缝长度方向纵向残余塑性应变的分布不均匀,在靠近起弧端和收弧端的区域呈现复杂的分布特征.焊接过程中温度场的变化和热源旁侧金属受力状况的不同是近缝区金属纵向塑性应变不均匀分布的原因.

Numerical simulation of longitudinal plastic strain field in thin-plate weldment of aluminum alloy

The welding longitudinal plastic strain field was simulated by elastic-plastic FEM analysis software. The simulation results showed that,for butt weldment made of 2A12-T4 aluminum alloy thin plates with 200 mm in length,100 mm in width and 2 mm in thickness,only longitudinal tensile plastic strain exists in the weld metal after welding,while in the zone close to the weld,not only longitudinal compressive plastic strain but also longitudinal tensile plastic strain exist. The distribution of residual longitudinal plastic strain along the welding seam is not uniform,especially complex at the zone near the ends of weld seam. The uneven distribution of longitudinal plastic strain in the zone close to the weld can be attributed to the combination of the variation of temperature field with the difference of load-carrying state of the metal beside the heating source during welding.