A perturbation method for the determination of the buckling strength of imperfection-sensitive structures Original Research Article

A perturbation method for determining the buckling strength of imperfection-sensitive structures is presented. The method is based on an extended system which was first used by Seydel in computation of limit points of nonlinear systems. The effects of various possible sources of structural imperfections on perfect structures with simple buckling loads are investigated by the method. The derivations and results of the present exposition are equally applicable to discrete and continuous systems. In the finite element implementation of the new formulation, the perturbation expansions are determined by solving numerically several linear problems with a single positive-definite sub-stiffness matrix. The method is illustrated with its application to the analyses of imperfection-sensitivity of a simply supported column on a linear-elastic foundation subjected to axial compression.