Buckling and post-buckling behavior of thin-walled cylindrical steel shells with varying thickness subjected to uniform external pressure

Abstract

In the present paper, numerical and experimental investigation have been undertaken into the buckling and post-buckling behavior of thin-walled cylindrical steel shells with varying thickness subjected to uniform external pressure. For the experimental study, four different cylindrical steel shell specimens with varying thickness were tested to collapse. For the post-buckling analysis of these structures, material and geometric nonlinear collapse analysis are carried out. To trace the equilibrium paths through limit points into the post-critical range, the ‘Arc-Length-Type Method’ has been used. In order to verify the accuracy and validity of the finite element modeling, the numerical results, obtained from nonlinear finite element collapse analyses, have been compared with the results of the experimental study. The study shows that the theoretical behavior predicted by the nonlinear finite element collapse analyses followed closely the experimental behavior. Consequently, it has been found that the finite element model is reliable enough to be used to undertake nonlinear analyses for investigation into the buckling and post-buckling behavior of thin-walled cylindrical steel shells with varying thickness. Also it has been found that the buckling mode can be generated in whole length of the shell if the thickness variation is low. However, in the case of high variation of thickness, the buckling mode is formed in thinner part only. Also, the considerable effects of circumferential and vertical weld line on the buckling strength and mode shapes are verified.