Compression Buckling Behavior of 7075-T6 Aluminum Skin Stiffened Panels Fabricated by Friction Stir Welding 2005-01-3322

Friction Stir Welding (FSW) of skin stiffened structures is being developed as a rivet replacement technology in the aerospace industry. Preliminary research was done on compressive strength and deformation characteristics of FSW aluminum skin stiffened panels. 7075-T6 aluminum sheets were bent to form stiffeners and friction stir welded to 7075-T6 aluminum sheets to fabricate two FSW panels. Another stiffened panel of similar dimensions was made by using traditional riveting. The compression test results and the failure modes of the panels are presented in this paper. The tests revealed that the FSW panels failed at approximately 17% higher load than the riveted panel. The failure loads of the FSW test panels were within 3 to 10% of the predicted load obtained by using two existing theoretical methods, and the failure load of the rivet panel was within 11 to 20% of the predicted load.