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采用热弹塑性有限元法对焊缝与母材线膨胀系数匹配对焊接过程中的动态应力以及残余应力的影响规律进行研究。在相同焊接热源模型和热输入量作用下的计算结果表明，焊缝与母材等胀匹配时，焊缝中心的纵向残余应力σx为拉应力。其值随母材屈服强度变化。较低时，焊缝中心σx能达到；而较高时，焊缝中心σx明显低于。当焊缝与母材低胀匹配时（αw＜αP），焊缝中心σx值低于，且随αw的减小而减小，并有可能由残余拉应力转变为压应力；而当焊缝与母材高胀匹配时（αw＞αP），焊缝中心σx值还与焊缝应变硬化指标Hw’有关，Hw’较低时，焊缝中心σx值在达到后不再升高，Hw’较高时，焊缝中心σx值可超过。
The influence of the dynamic elastic-plastic finite element method on the dynamic stress and the residual stress in the welding process of the matching of the linear expansion coefficient of the weld and the base metal was studied. The calculation results under the same welding heat source model and heat input amount show that the longitudinal residual stress σx in the weld center is the tensile stress when the welding seam matches with the base metal. Its value varies with the yield strength of the base metal. At lower values, the center σx of the weld is reached, whereas at higher values the center σx of the weld is significantly lower. When the welds match the low expansion of the base metal (αw <αP), the σx value of the weld center is lower than the value of αw and decreases with the decrease of αw, and it is possible to change from residual tensile stress to compressive stress. And the base metal high expansion (αw> αP), the weld center σx value is also related to the weld strain hardening Hw ’, when Hw’ is low, the weld center σx value no longer increases after reaching Hw ’ Higher, the weld center σx value can be exceeded.