Remarkable postbuckling paths analyzed by means of the consistently linearized eigenproblem

In addition to the determination of load levels at critical points of stability problems, frequently the post-buckling behavior is of interest. For non-linear problems, the so-called consistently linearlized eigenvalue problem is a suitable tangent linearization method, which facilitates determination of stability limits. The solution process of the eigenproblem is significantly simplifed by appropriate coordinate transformations. With this process, characteristic shapes of eigenvalue curves allow identification of bifurcation buckling modes, snap-through modes, and hilltop buckling modes. Mathematical properties of the eigenvalue curves are addressed and conclusions regarding the shape of postbuckling paths are drawn. Consideration also touch upon the conversion from imperfection sensitivity into insensitivity. The theoretical findings are corroborated by examples dealing with a von Mises truss and a similar discrete system, showing a remarkable postbuckling behavior such as a zero-stiffness equilibrium path. For both systems, the same approach of stiffness increase allows conversion from imperfection sensitivity into insensitivity. Copyright (C) 2008 John Willey & Sons, Ltd.