RESEARCH ON WELDING SPOT FAILURE OF HIGH STRENGTH STEEL AND NUMERICAL SIMULATION
By using inverter resistance welding machine,qualified welding spots were obtained by optimizing welding process parameters,and the diameter of molten core was 6.14 mm.The mechanical properties of welding spots under different stress states were obtained by shear tensile,cross tensile and peel tensile tests.The maximum shear tensile force was 16.27 kN,the maximum cross tensile force was 5.48 kN and the maximum peel tensile force was 1.28 kN.Based on Ls-dyna,the simulation models of shear tensile test,cross tensile test and peel tensile test of welding spots were established.The beam element and solid element were used to simulate welding spots respectively.According to the failure criterion of welding spots of force,appropriate welding spot failure parameters were obtained through simulation benchmarks.The results show that the failure parameters of beam element and welding spot are different due to the different welding spot simulation methods adopted by beam element and solid unit.When the beam element is used,the axial force failure parameter of the high-strength steel DP980 welding spot is 5.6 kN,the shear force failure parameter is,and the bending moment failure parameter is 11.5 kNm·m.When the solid element is used,the axial force failure parameter of the high-strength steel DP980 welding spot is 5.5 kN,the shear force failure parameter is 28 kN,and the bending moment failure parameter is 12 kN·mm.High simulation accuracy can be obtained by using force-based failure criteria of welding spots.The maximum simulation errors of shear tensile,cross tensile and peel tensile of solder joints are all less than 1％.
high strength steelwelding spotfailure modelnumerical simulationshear force
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