PNNL

Abstract

This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of aluminum spot welded samples using a combined experimental, statistical and analytical approach. Static strength tests using coupon configurations of lap shear, cross tension and coach peel were performed on joint populations with a controlled fusion zone size. The resulted peak load and energy absorption levels associated with each failure mode were studied using statistical models. An analytical model was developed to determine the failure mode of an aluminum resistance spot weld based on limit load analyses. It was found that fusion zone size, sheet thickness, and the level and location of weld porosity/defects are the main factors influencing the cross-tension failure mode of an aluminum spot weld.