Single perturbation load approach: new definition for P1 and explaining the constancy of the buckling load

Abstract

The single perturbation load approach is a deterministic analysis method applied in the determination of design loads for imperfection sensitive structures. As verified by Hühne et al., imperfection sensitive cylindrical structures when subjected to axial compression will exhibit a progressively decreasing load carrying capacity for growing imperfection amplitudes up to a threshold, where the buckling load remains nearly constant. The method was named single perturbation load because a unitary lateral load is used to create the geometric imperfection, and the threshold perturbation load beyond which the buckling load is nearly constant is called P1. The aim of the present paper is to summarize what has been presented by Castro et al., explaining the constancy of the buckling load and giving a precise definition for the threshold perturbation load P1.