Elastic stability and imperfection sensitivity of axially loaded cylindrical shells on narrow supports

Abstract

In this paper the elastic stability and imperfection sensitivity of axially loaded cylindrical shells on narrow discrete supports is explored. This is done by parametric geometrically nonlinear finite element analyses of the perfect and imperfect cylinders up to the critical load maxima. In addition, classical buckling eigenvalues are computed for reference purposes. The obtained numerical results are plotted in a systematic unified way and related curve-fit expressions are developed for the critical load maxima in dependency of the geometrical parameters of the problem. The support width, the shell slenderness and the type of local support, i.e. flexible versus rigid local support conditions, are varied. The present basic investigation is restricted to shells with linear-elastic material behaviour. The study of the buckling behaviour for narrow local supports, including the limiting case of point supports is of special concern. Strictly speaking, point supports exist only in the mathematical limit, since the stress singularities which occur in this case are mere artefacts and have no direct physical significance. But it turns out that the local buckling behaviour, like shape and evolution of buckles, magnitude of buckling loads etc. tends to an invariant typical limiting scenario, which is surprising but understandable at the same time. This typical local mono–modal buckling scenario, which is also investigated and presented in this paper, may be viewed as the counterpart to the well–known multi–modal characteristic global buckling scenario which occurs under uniform axial compression.