Postbuckling analysis of thin plates on an elastic foundation by HT FE approach

The paper presents a hybrid-Trefftz (HT) element approach for the numerical solution of postbuckling analysis of thin plates on an elastic foundation. The approach is based on a modified variational principle and Trefftz functions. Exact solutions of the Lame-Navier equations are used for the in-plane intraelement displacement field, and an increment form of the basic equations is adapted With the aid of the incremental form of these equations, all nonlinear terms may be taken as pseudo-loads. Moreover, some modifications have been made on the nonlinear boundary equations to simplify the ensuing derivation. As a result the in-plane and out-of-plane equations are uncoupled and then the derivation for the HT finite element (FE) formulation becomes quite simple. The practical efficiency of the new element model has been assessed through two examples. (C) 1997 by Elsevier Science Inc.