Mode interaction in axially stiffened cylindrical shells

Abstract

Postbuckling behavior and imperfection sensitivity associated with mode interaction in axially stiffened cylindrical shells under axial compression are studied. The two modes considered are an overall mode with wavelengths that are long compared to stiffener spacing and a short-wavelength panel mode involving buckling between the stiffeners. A restricted optimization study is made where the number of stringers is treated as a design parameter, and the range of designs considered includes the optimum design for the perfect shell, where the two modes are simultaneous. The influence of a given level of imperfections on the optimum is explored. A general method for analyzing initial postbuckling behavior is proposed for structures with simultaneous or nearly simultaneous modes. Asymptotic expansions of all fields in the amplitudes of the competing modes provide a set of uniformly valid results.