铝合金MIG焊L形接头的有限元分析及试验验证

Finite element analysis and experimental verification of L-joint for aluminum alloy

以12 mm厚轨道车辆用铝合金板多层多道MIG焊为研究对象,采用热弹塑性有限元分析和试验验证的方法进行研究。采用更符合实际工况的边界条件简化方法,建立了L形接头单边V形坡口的有限元模形,模拟并分析了L形接头焊接过程中的温度场、应力场和焊接变形,发现有限元法可准确模拟多道焊的热积累效应,预测焊接构件的残余应力和变形分布;同时开展了L形接头多层多道MIG焊试验,并采用盲孔法测量焊后残余应力,对比模拟和实测结果发现,模拟和实测的残余应力在变化趋势和峰值上吻合良好,验证了数值模拟模形的准确性。

The aluminum alloy plates of 12 mm in thickness in railway vehicles welded by multilayer multi-pass MIG welding was studied by using the elastic-plastic finite element method combined with experimental measurement.By utilizing a more accurate boundary condition simplified method,a unilateral V groove multilayer multi-pass welding finite element model of L-joint was set up to analyze the welding temperature field,residual stress distribution and deformation trend.The results show that the heat accumulating effect of multi-pass welding,welding residual stress and distortion can be accurately simulated by the finite element method.Simultaneously,multilayer MIG welding of L-joint was carried out and the residual stress was measured by the blind-hole method.Simulating results are in good agreements with the actual welding results,which verifies the reasonability of the finite element model.