考虑侧壁热源的摇动电弧窄间隙GMA焊接温度场有限元模拟

Finite Element Simulation of Temperature Field in Swing Arc Narrow Gap GMA Welding Considering Sidewall Heat Source

基于新型摇动电弧窄间隙熔化极气体保护(GMA)焊的电弧偏转现象,将在侧壁停留时的电弧热源分解为电弧分热源和侧壁热源,建立了考虑侧壁热源的热源模型,采用ANSYS软件建立新型摇动电弧窄间隙GMA焊的有限元模型,对考虑侧壁热源和未考虑侧壁热源时焊接接头横截面熔合线轮廓以及热循环曲线进行模拟,并进行试验验证;采用有限元模拟方法研究了考虑侧壁热源时摇动电弧窄间隙GMA焊接过程中的温度场,并与未考虑侧壁热源时的温度场进行对比。结果表明:模拟得到考虑侧壁热源时焊缝横截面左右两侧壁熔合线最高点的深度与试验结果间的差值小于未考虑侧壁热源时;考虑与不考虑侧壁热源2种条件下,焊接接头不同测试点的热循环模拟曲线的变化趋势与试验结果基本吻合,峰值温度的最大相对误差分别为1.8%和3.4%。考虑侧壁热源的热源模型能更加准确地描述摇动电弧窄间隙GMA焊过程中的热源分布特征。考虑侧壁热源模拟得到的底部熔深略小于未考虑侧壁热源时,而侧壁熔深则略大,但尺寸变化均小于0.1 mm;温度场稳定前,考虑侧壁热源时熔池的形成规律与不考虑侧壁热源的基本一致,但接头上表面的熔池尺寸略小,而温度场稳定后,接头上表面的熔池尺寸也基本一致。

Based on the arc deflection of the new type swing arc narrow gap melting electrode gas shield(GMA)welding,the arc heat source staying at the sidewall was decomposed into arc component heat source and sidewall heat source,and the heat source model considering the sidewall heat source was established.The finite element model of the new type swing arc narrow gap GMA welding was established by ANSYS software.The cross-section fusion line profile and thermal cycle curve of welded joint with and without considering sidewall heat source were simulated and verified by experiments.The temperature field in the swing arc narrow gap GMA welding with considering sidewall heat source was studied by the finite element simulation method,and was compared with that without considering sidewall heat source.The results show that the difference between the depth of the highest point of the fusion line on the left and right sides of the weld cross section by simulation with considering sidewall heat source and the test result was smaller than that without considering sidewall heat source.The variation trend of the thermal cycle curves at different test points of the welded joint by simulation with and without considering sidewall heat source was basically consistent with the test results,and the maximum relative errors of peak temperatures were 1.8%and 3.4%,respectively.The heat source model considering the sidewall heat source could more accurately describe the heat source distribution characteristics in the swing arc narrow gap GMA welding.The bottom weld penetration depth by simulation with considering sidewall heat source was smaller than that without considering the sidewall heat source,and the side weld penetration depth was larger,but the size change was less than 0.1 mm.The formation law of the molten pool before the temperature field stabilization was the same as that without considering the sidewall heat source,but the molten pool size on the upper surface of the joint was smaller;after the temperature field was stabilized,the molten pool size on the upper surface of the joint was the same.