Progress in laser beam welding of aircraft fuselage panels / skin-skin-connections

The most challenging objective for future metallic fuselages is to reduce weight and to obtain lower production costs in comparison to CFRP-Materials. On the metallic side, Airbus established successful laser beam welded stringer-skin-joints in the lower fuselage to overcome current limitations of conventional riveting techniques. The paper presents the results of a study to improve damage tolerance for laser beam welded skin-skin-joints, concerning a new weld seam path in relation to the strength mismatch of the weld. The used aluminum alloy was the AlMgSiCu (6xxx) material what provides good weldability, around 3 % weight reduction compared to the standard alloy AlCu (2024). Special attention will be focused on the damage tolerance behavior. The obtained advantages of the skin-skin-joints are: . a damage tolerance behavior of LBW joints comparable to the base material . a weight saving potential of at least 10 % compared to riveted structures . enhanced structural properties such as stiffness and corrosion resistance compared to conventional riveting techniques. A further benefit is the possibility to transfer the solutions for improved damage tolerance to other welding techniques such as friction stir welding (FSW). First promising results show that the damage tolerance between LBW and FSW is almost comparable.