The Research And Application Of Welding Process’ Numerical Simulation Based On Marc

Welding is a very important material connection technology in modern production. Thewelding joint quality has a big impact on welding performance. The reaserch, which is aboutthe welding temperature field and stress field, will provide a great help for improving thewelding technology, the quality of welds and guaranteeing the welding strength. The purposeof the study is to improve the accuracy of the numerical simulation by improving parameterselection method of heat source model, so as to obtain a better welding temperature field andstress field, which is applied to improving and guiding the welding technology.Firstly, this article made a summary of the butt-weld joints meshing method, theparameter selection method of heat source model and the method of setting boundarycondition. Secondly, we made the ansys about the heat source model’s characteristics andapplication. On the base of the formers’ work, the method, which was used to selecting theparameter of the double ellipsoid heat source model, was put forward and verified with theexperimental data in the literature. Finally, this methord was applied on the ansys of thedifferent effect on the weld pool shape and residual stress between the considering addingmaterial simulation method and the not considering adding material simulation method. Theresult showed that the considering adding material simulation method’s weld poor shape andresidual stress distribution was better than the not considering adding material simulationmethod’s.The welding process numerical simulation method had not been applied on improving thewelding technology until its rightness was identified. First of all, the numerical simulation ofinvariant speed welding showed that there was incomplete fusion defect in the shootout phase.For that matter, the study on variable-speed welding was started, with which the incompletefusion defect was avoided by reducing the welding speed at the shootout phase. And then, onthe base of the formers’ formulas we got the martensite transformation temperature, whichwas used to adjust the welding cooling time and slow down the cooling rate with the secondwelding’s reheating effect on the first welding, so as to avoid the formation of the martensite.This technology could prevent from producing the weld cold cracking effectively. In the end,we made a contrast of the welding deformation and residual stress between the V-grooveorderly single-sided welding and the X-groove symmetric double-sided welding. The resultshowed that the V-groove orderly single-sided welding got lager angular deformation, smallerresidual stress and better residual stress distribution than the X-groove symmetricdouble-sided welding. So in the actual welding we should pay more attention to control theangular deformation with the V-groove orderly single-sided welding and relieve the residualstress with the X-groove symmetric double-sided welding.