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总结了计算焊接温度场过程中焊接热源模式的改进过程。首先讨论了传热学中常用的以集中热源为基础的线热源与面热源的解析模型、以及能量在空间以高斯函数形式分布的焊接热源模式 ,以高斯分布函数为基础 ,引出了半球能量密度分布的热源模式、椭球能量密度分布的热源模式、双椭球能量密度分布等焊接热源模式。并对比了不同热源分布函数对计算结果的影响 ,讨论了不同焊接计算过程中对热源函数的选择。结果表明 ,通常的工程运算仍可采用解析模型函数进行简化计算 ,高斯分布函数、半球能量密度分布函数、椭球能量密度分布函数常应用在有限元计算过程中 ,但由于未精确考虑电弧对熔池的冲击作用 ,在熔池附近有一定误差 ,而双椭球能量密度分布的热源模式 ,不仅可以处理一般的电弧冲力小的焊接热源 ,也可以处理具有强烈穿透作用的激光焊和电子束焊过程的焊接热源 ,进一步提高焊接热循环的计算精度。
The improvement process of welding heat source mode in calculating welding temperature field is summarized. Firstly, the analytical model of heat source and surface heat source based on central heat source, which is commonly used in heat transfer, and the welding heat source mode in which energy distributes in the form of Gaussian function are discussed. Based on the Gaussian distribution function, the energy density Distributed heat source mode, ellipsoidal energy density distribution of heat source mode, double ellipsoidal energy density distribution and other welding heat source mode. The effects of different heat source distribution functions on the calculation results are compared. The selection of heat source function in different welding processes is discussed. The results show that the general engineering calculation can still be simplified by the analytic model function. The Gaussian distribution function, the hemispherical energy density distribution function and the ellipsoid energy density distribution function are often used in the finite element calculation process. However, However, the heat source mode with double ellipsoid energy density distribution can not only handle the welding heat source with small arc impulse but also deal with laser welding and electron beam with strong penetrating effect Welding process welding heat source, to further improve the calculation accuracy of the welding thermal cycle.