中文摘要：

通过高速摄像对正、负极性等离子弧形态进行分析,并分析变极性等离子电弧正、反极性不同产热机理的基础上,采用＂高斯＋双椭球＂组合热源模型,建立正、反极性期间不同热源模型。采用ANSYS参数化设计语言（ANSYS parametric designlanguage,APDL）编程语言实现与实际变极性焊接参数对应热载荷的循环交替加载,计算出铝合金变极性等离子弧焊接温度场及熔池形状。对比分析不同变极性电流和焊接速度条件下焊接熔池的穿透深度,并通过实际焊接试验验证热源模型的准确性。研究结果为准确掌握铝合金变极性等离子弧热源形态、产热机理和等离子弧力等特性,并合理选择焊接工艺参数提供理论依据。

英文摘要：

Based on analysis of plasma arc shape by high-speed camera and thermogenesis mechanism in positive and reverse polarity period,the models applied with Gaussian plus double ellipsoid combine heat source model are built.Using ANSYS parametric design language（APDL） programming language achieved alternative cycles of heat load that corresponding to the actual variable polarity welding parameters,and calculating the temperature field and molten pool shape of aluminum alloys variable polarity plasma arc welding.Comparing molten pool penetration depth under different currents and welding speeds,and verifying the heat source model accuracy in actual welding.The results provides theoretical basis to the characteristics of variable polarity plasma arc heat source shape,thermogenesis mechanism and polarity plasma arc force,and conduces to select reasonable welding parameters.