Tracing secondary equilibrium paths of elastic framed structures

For a framed structure that is subjected to bifurcation buckling, it may be useful to trace its secondary equilibrium path to gauge its sensitivity to geometric imperfections or to study the nature of load shedding from the b uckled structure. For this purpose, a substantial number of branch-switchin g algorithms for tracing the secondary equilibrium paths of elastic structu res have been proposed in the literature. However, virtually all of the pub lished algorithms have heavy mathematical overtones that are not readily ap preciated by practicing structural engineers. This paper presents a simple and efficient branch-switching algorithm that is explained in more easily u nderstood terms. The proposed algorithm is demonstrated through numerical e xamples to be effective in tracing the secondary equilibrium paths of vario us framed structures with different types of postbuckling behaviors.