激光+GMAW复合热源焊焊缝成形的数值模拟Ⅱ.组合式体积热源的作用模型

根据激光 脉冲GMAW电弧复合热源焊焊缝横断面的形状特点,从宏观的传热过程出发,提出了4类新颖的、适用的组合式体积热源的作用模式.将电弧热、熔滴热焓和激光热能分别描述为双椭圆分布,双椭球体分布和峰值热流递增-曲面旋转体分布.将适用的组合式体积热源作用模式应用于复合焊的温度场数值分析,计算出了不同工艺条件下的复合焊焊缝形状尺寸,与实测结果进行了对比,两者吻合情况良好.所建立的4类组合式体积热源充分考虑了复合焊的工艺特点,对焊缝形状尺寸的数值模拟精度较高,能定量体现温度场的变化规律.

NUMERICAL SIMULATION OF WELD FORMATION IN LASER+GMAW HYBRID WELDING,II. Combined Volumetric Distribution Mode of Hybrid Welding Heat Source

Based on the geometry characteristics of laser+GMAW-P hybrid welds and the macroscopic mechanism of heat transfer, four new kinds of adaptive combined volumetric heat source modes are developed The arc heat flux, thermal content of overheated droplets, and laser power are described as double-elliptic plane distribution, double-ellipsoid body distribution, and peak value increasing-rotary curve body distribution, respectively. To apply the developed adaptive combined volumetric heat source modes into numerical analysis of temperature profiles in hybrid welding, the geometry and dimension of hybrid welds are predicted under different conditions. Through comparing the calculated results to the experimental measurements, it is found that both match well. The four kinds of adaptive combined volumetric heat source modes fully consider the process features of hybrid welding, can numerically simulate the weld geometry and dimension accurately, and reflect quantitatively the varying regularity of temperature profiles in hybrid welding.