Buckling of unilaterally constrained columns by complementarity eigenvalue analyses

A numerical approach for the study of the elastic buckling of slender columns with unilateral supports is proposed. This new approach is based on the numerical solution of a special type of eigenvalue problems that takes into account the complementarity character of the pair (displacement, obstacle reaction) at each unilateral support. The implementation of the proposed approach is illustrated by the determination of bifurcation loads and corresponding modes for several finite element models of columns.