A PERTURBATION METHOD FOR THE DETERMINATION OF THE BUCKLING STRENGTH OF IMPERFECTION-SENSITIVE STRUCTURES

A perturbation method for determining the buckling strength of imperfe ction-sensitive structures is presented. The method is based on an ext ended system which was first used by Seydel in computation of limit po ints of nonlinear systems. The effects of various possible sources of structural imperfections on perfect structures with simple buckling lo ads 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 seve ral linear problems with a single positive-definite sub-stiffness matr ix. The method is illustrated with its application to the analyses of imperfection-sensitivity of a simply supported column on a linear-elas tic foundation subjected to axial compression.