Buckling load reduction of axially compressed cylindrical shells under the action of two interacting localized defects

Abstract

The effect of two localized axisymmetric initial imperfections on the critical load of elastic cylindrical shells subjected to axial compression is studied through finite element modelling. This was carried out by means of the specialized shell buckling package Stanlax. First, a single defect having a triangular geometry is considered in order to determine the most adverse defect configuration, then two defects having this arrangement and which are symmetrically distributed along the shell length are introduced in the problem in order to assess their global interacting effect on the buckling load reduction. A statistical approach which is based on full factorial design of experiment tables and analysis of variance is used to quantify the relative influence of all the intervening factors. It is shown that two interacting defects yield further reduction of the shell critical load.