Buckling load variability of cylindrical shells with stochastic imperfections

Abstract

In this paper, the effect of random initial geometric, material and thickness imperfections on the buckling load of isotropic cylindrical shells is investigated. To this purpose, a stochastic spatial variability of the elastic modulus as well as of the thickness of the shell is introduced in addition to the random initial geometric deviations of the shell structure from its perfect geometry. The modulus of elasticity and the shell thickness are described by two-dimensional univariate (2D-1V) homogeneous non-Gaussian translation stochastic fields. The initial geometric imperfections are described as a 2D-1V homogeneous Gaussian stochastic field. A numerical example is presented examining the influence of the non-Gaussian assumption on the variability of the buckling load. In addition, useful conclusions are derived concerning the effect of the various marginal probability density functions as well as of the spectral densities of the involved stochastic fields on the buckling behaviour of shells, as a result of a detailed sensitivity analysis.