Safety of optimally designed structures like cylinders and plates

Abstract In the minimum weight designs, the influence of initial imperfection and suddenly applied loads undermine the presumed safety of cylinderical shells and, on the other hand, the contribution of post-buckled strength enhances the safety of plates. The safety margin for both the structures is reduced due to the interaction of buckling and frequency constraints. These well known phenomena are examined with relation to the structural safety for the benefit of practical designers with the help of two design examples; one a stiffened cylinder and the other a waffle plate.