基于有限元计算软件MARC，对16 mm厚低合金高强钢激光填丝多层焊温度场和应力场进行了三维数值模拟。利用生死单元法，采用热流密度线性衰减高斯圆柱热源模拟匙孔效应，双椭球模型模拟焊丝受热过程。计算结果与实际结果对比，两者基本吻合。计算结果表明，层间保温能够有效降低接头冷却速度，减小激光填丝焊残余应力，改善厚板多层焊接头性能；多层焊应力集中主要位于中下部焊道及其热影响区；焊接中坡口有收缩趋势，焊后工件有一定角变形。

A three-dimensional model is developed for numerical analysis of the temperature and stress fields in wire filling laser multilayer welding on high strength steel of 16 mm in thickness by the MARC software. During the calculation, with the technique of element birth and death, the Gaussian cylindrical heat source of heat flux linear attenuation and the double ellipsoid heat source are used to simulate the keyhole effect and the filler wire heating process, respectively. Predicted results are in good accordance with the experimental data. The results show that interlayer heat insulation can effectively reduce the cooling rate of the welded joint and decrease the residual stress, which improves the properties of welded joint. The stress concentration is mainly located in the lower part of the weld; the groove tends to shrink in welding and the work piece exhibits a certain angular distortion after welding.