Numerical Analysis Of Resistance Spot Welding Process Of High Strength DP600 Steel

Sheet steel welding structures are widely used in engineering production practice,especially in the production of some of the important parts of vehicles. For example, thebody and frame are manufactured through the welding of sheet steels. Welding qualitydirectly influences the overall quality of the vehicle. Therefore, the study of the weldingquality of sheet steel welding structures has very important significance.Through Finite Element Method (FEM), this paper researched the DP600 sheetstructures joined by Resistance Spot Welding (RSW). After the pre-press process, contactareas got determined. Then the transient thermal analysis was conducted, during whichthe contact resistances at both the sheet-sheet and the sheet-electrode interfaces weretreated as a function of temperature. The RSW processes of sheets with equal thicknesswere analyzed, then the electric field and temperature field were obtained. It is validatedthat the model is reasonable and the simulating result is exact by the checking of nuggetshape and dimension in practical spot welding.Based on the thermoelectric analysis, thermal-elastic-plastic analysis of the resistancespot welding was conducted. Finite element calculations were used to get the contactpressure distribution at each contact interface, as well as the rules of the variation ofstress and strain and the deformation of welding joints. About the resistance spot weldingof DP600 sheets with same thickness, for the symmetrical characteristics of the geometry,local deformation of the model during the welding process will not affect theoverall deformation.In addition, based on the accuracy of the numerical simulation of the welding of twolayers with equal thickness, the numerical simulations of the welding of two layers withdifferent thicknesses and three layers with equal thickness were conducted to get theshape of the weld nugget and the temperature field distribution, which were used to guidepractice.