基于高斯热源的T型接头焊接数值模拟

Numerical Simulation of T Joint Welding Based on Gauss Heat Source

针对重要焊接构件T型接头的焊接问题,讨论了焊接热源应用情况。采用高斯热源模型,建模并划分网格,确定相应的焊接工艺参数并选用合理的材料热物理性能条件,利用有限元法模拟焊接过程,分析了s355j2g3钢T型接头的焊接温度场、应力场,探讨了温度场的变化规律。高斯热源模型模拟等离子弧焊较为合理,焊后应力最大值未出现在焊缝上,而是出现在横板和立板贴近焊缝的热影响区部位,焊接应力的最大值处于焊件的表面,由外到内逐渐衰减,焊后残余应力主要为拉应力,数值较大,作用范围很小且衰减迅速,结合焊缝末端节点以及整个焊缝的温度循环曲线,分析了晶相转变及焊缝组织,发现其主要金相组织为贝氏体及马氏体,其他相较少。该研究为T型焊接接头的性能研究提供了有力的帮助。

According to the welding problem of T joint of important welding components,the application of welding heat source is discussed,Gauss heat source model is used for modeling and meshing to determine the corresponding welding parameters and select the reasonable thermal physical properties conditions of materials,the welding process is simulated by using the finite element method,the welding temperature field and stress field of T joint of s355j2g3 steel are analyzed,the variation regulation of temperature field is studied.The results indicate that Gauss heat source model is reasonable for simulating plasma arc welding and the maximum stress is not appeared in the weld seam,but appeared in the heat affected zone of transverse plate and vertical plate close to the weld seam,the maximum welding value is appeared on the welding surface,it decreases gradually from the inside to the outside.The welding residual stress is mainly tensile stress with high value and very small scope and rapid decay.Combined with the end node of the weld seam and temperature cycling curve of the whole welding seam,the transformation of crystal phase and welding structure are analyzed.It is found that the main metallographic structure is Bainite and Martensite,the other phases are relatively few.It provides powerful help for the research of the performance of T joint welding.