Tracing the equilibrium path beyond compound critical points

Procedures to handle critical points with coincident or nearly coincident b uckling loads in a geometrically nonlinear continuation process are present ed. The proposed branch switching algorithm is based on a Liapunov-Schmidt- Koiter-type asymptotic reduction which is used for the prediction step into the post-buckling range. A critical review of the existing methodology for the numerical treatment of post-bifurcation branches at a multiple bifurca tion point is also given. In the review the main emphasis is given to robus tness, but also implementational issues and computational requirements are addressed. Some modifications to the existing algorithms are proposed in or der to improve their robustness or efficiency. Numerical examples of a flat plate and a thin-walled structure are shown. Copyright (C) 1999 John Wiley & Sons, Ltd.