Static test simulation of refill friction stir spot welded and riveted coupons using finite element analysis

Abstract

Refill Friction stir spot welding (RFSSW) produces a solid-state lap joint between sheet metals, preferably aluminum alloys, without leaving behind an exit hole in the workpiece. This joining technique was derived from friction stir spot welding (FSSW). RFSSW has been demonstrating a potential for replacing conventional joining techniques, such as riveting, resistance spot welding, and fastening. The goal of the research is to compare stress distributions and failure mechanisms of the joints produced by RFSSW and riveting. The experimentation involved finite element simulations of static loads applied to RFSSW coupons and riveted coupons in the directions of lap shear and cross tension. To validate the simulation results, actual coupons were produced and mechanically tested. The study used a robotic RFSSW system developed by Kawasaki Heavy Industries (KHI) for producing RFSSW coupons. The stress distributions estimated by the finite element simulations were in a good agreement with the failure mechanisms demonstrated by actual coupons during mechanical tests. Keywords: Refill Friction Stir Spot Welding, Riveting, Aerospace, FEA, ABAQUS