Tuning residual stresses in welded structures by exploiting bio-inspired suture interfaces

Abstract

Nature offers a valuable source of inspiration when designing optimized structures. For instance, when two or more shells are joined during growth processes, Nature prefers to exploit interlocking paradigms to enhance the strength of the bond—cranial sutures are one example. Mimicking this distinctive characteristic when welding thin metallic elements may offer some structural benefits. The present study theoretically investigates the possibility of mitigating the detrimental tensile residual stress that always originated by welding processes, by exploiting Computational Welding Mechanics. Specifically, two plates joined by laser welding following sinusoidal paths (i.e., wave-like), alongside a linear one, will be studied and compared. Thanks to the distinctive temporal and spatial heat distributions of sinusoidal welding, both welding stress and strain develop in dissimilar ways compared with linear path welding—this is reflected to the resulting weldment distortion too. The results show that geometrically optimized sinusoidal welding can effectively reduce residual stress magnitudes compared with the linear configuration counterpart. The implications of these findings are of particular interest when dealing with the structural performance of welded structures, especially in fatigue contexts.