Effect of Nugget Size on Stress Distribution in Weld-bonded Single Lap DP 600 Steel Joint

The effect of the nugget size from 2 mm to 8 mm in the lap zone of the adherend on the stress distribution in weld-bonded single lap DP 600 steel joint was investigated using elastic finite element method (FEM). The results from the numerical simulation show that the value of the peak stress along the bondline at the center of lap zone increases a little when the larger nugget is arranged but the width of the peak stress is increased greatly as the nugget size increased. It is suggested that a larger nugget arranged in the lap zone may be appropriate to optimize the stress distribution in the weld-bonded single lap DP 600 steel joint and its fatigue life would be longer than the joint that with a smaller one.