Effect of Dynamically Induced Radial-Displacement Perturbations on the Maximum Strength of Initially Imperfect, Circular Cylindrical Shells Under Constant-Rate End Shortening

摘要

The effects of dynamic perturbations on the maximum strength of initially imperfect, axially compressed, circular cylindrical shells are studied using a modified Hamilton's principle based on a Reissner-type functional, von Karman-Donnell shell kinematics, and a deformation theory of plasticity. The dynamic effects have been included by making use of the analogy of time-dependent imperfection growth to represent dynamic disturbance of the lateral motion of the shell wall. The results of the present analysis reflect families of load versus end-shortening curves for long circular cylinders. For each material, initial imperfection parameter, and radius-to-wall thickness ratio, there exist frequency-shortening rate ratios which provide unique load-end shortening paths in both the elastic and inelastic ranges. Significant maximum strength reductions are obtained for aluminum and stainless steel relative to the predictions of static elastic and inelastic theoretical analyses for shell radius-to-thickness ratios representative of closely stiffened and sandwich construction. (Author)