Experimental characterization of buckling load on imperfect cylindrical shells using the multiple perturbation load approach

Abstract

The paper present a discussion related to the use of the “Single perturbation Load Approach” (SPLA) as a methodology to represent geometric imperfection of imperfection sensitive shell structures prone to buckling. In this context, the paper compares the effect of the SPLA on the buckling load of composite cylindrical shells against an alternative methodology, which combines several perturbation loads in different positions, called “Multiple Perturbation Load Approach”. The aim of this paper is to investigate if the SPLA is the worst geometrical imperfection case scenario to be used for finite element simulation. Since the paper is based on experimental results, a benchmark case is developed using a composite cylindrical shell with a radius over thickness ratio of 400. The results of buckling load using one, two and three perturbation loads distributed along the surface of the cylinder shown that the less conservative knock-down factors are obtained by using SPLA