This paper is concerned with the dynamic plastic response and failure of a ring-stiffened cylindrical shell subjected to high intensity pressure loading. An approximate analytical solution is developed based on a simple computational model and some experimental observations of the final damaged structure. In particular, the magnitude of the transient and final shapes of the transverse deflections of the deformed shell and fracture initiation of the shell undergoing an explosive-type loading are predicted. The overall deflection of the shell consists of a global and a local (between stiffeners) component. The formulation of the principle of virtual work between stiffeners, led to the derivation of coupled equations of motion in two sub-systems: local or bay deformation and global or stiffener deformation. In order to predict shell failure, the solution for the transient deflection or denting of the cylinder was coupled with a simple fracture criterion. The analytical model showed good agreement with a limited amount of experimental data. Simple closed-form solutions was then obtained in terms of a single impulse parameter, which represents both the amplitude and decay constant for pressure loading. A parametric study for a given shell was performed to account for variable loading and stiffener parameters.

INTRODUCTION

This paper is concerned with the dynamic plastic response and failure of a cylindrical shell subjected to an explosive-type loading. This is a difficult mathematical problem in which the complexity of the overall shell deformation is further magnified by the presence of ring-stiffeners, which may undergo tripping and fracture during the explosion. Because of the difficulties in finding closed-form solutions to a set of coupled shell differential equations, past researchers have resorted to using empirical methods such as iso-damage curves [1, 2] or computer codes [3]. Some analytical solutions for the elastic response of the shell due to pressure loads have been found [4, 5, 6], but very little has been done in addressing the plastic response of the shell [7].

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