Buckling and failure analysis of FRP faced sandwich plates

A thin-walled sandwich plate having laminated composite faces and subject to axial compression is studied. The first part of the work is devoted to the discussion of the 2-D geometrically nonlinear formulation of governing equations with the use of the Hamilton and the Lagrange variational principles. It allows us to compare and verify values of buckling loads and natural frequencies obtained with the use of different variants of sandwich plate theory. The analytical results are also confronted with the FE computations conducted with the use of the NISA II package. Then, we consider also the problems of local failure damage of sandwiches basing on the 3-D FE analysis. The aim of those investigations is to point out the effects of the normal stresses and their influence on the sandwich behaviour. (C) 1999 Elsevier Science Ltd. All rights reserved.