The Effect of Circumferential Imperfections on Axial Load Carrying Capacity of Thin-Walled Cylindrical Shells

The load carrying capacity, buckling and post-buckling behavior of cylindrical thin-walled shells exposed to axial loads are very sensitive to imperfections in the initial geometry. These imperfections are invariably caused by an assortment of manufacturing processes like displacing, installing or welding; one of the most important imperfections caused by welding that has been reported to have an essential detrimental effect on the buckling resistance of these shells under axial load is circumferential imperfections. Despite many determinations of the effect of imperfections on axial load carrying capacity of cylindrical thin-walled shells, the major part of these studies are concentrated on the existence of imperfections on the shell wall, and a comprehensive research on circumferential imperfections and their effects on axial load carrying capacity has not been performed. This is the main subject of this research. Also in this paper, the interaction of two imperfections on each other and on the load carrying capacity of cylindrical shells in various cases are analyzed and determined using a finite element program (ABAQUS).