Fatigue life simulation of spot weld based on equivalent structure stresses

The fatigue life of spot-welds are predicted based on the stress-based method for tension shear and coach peel samples,the simplified beam、shell and rigid beam ware used to built the FE model of spot-weld,the grid force of elements around spot-weld nut ware gotten from elastic FE analysis using commercial software,the equivalent structure stresses were calculated using line force and moments,the fatigue life of spot-weld of tension shear and coach peel were predicted based on master S-N curve.The physical fatigue tests have been done to valid the simulation results.The results indicted that the prediction of spot-weld fatigue life based equivalent structure stresses had satisfactory approximation and could be used to predict the spot-weld fatigue life of body in white in automotive industry.