BUCKLING AND POSTBUCKLING OF CIRCULAR PLATES CONTAINING CONCENTRIC PENNY-SHAPED DELAMINATIONS

Buckling and postbuckling analyses of circular laminated composite pla tes with delaminations are presented. An axisymmetric finite element m odel based on a layer-wise laminated composite plate theory is develop ed to formulate the problem. Geometric nonlinearity in the sense of vo n Karman and imperfections in the form of initial global deflection an d initial delamination openings are included. A simple contact algorit hm which precludes the physically inadmissible overlapping between del aminated surfaces is proposed and incorporated into the analysis. Nume rical results are obtained addressing the effects of the initial imper fections, the number of delaminations and their sizes on the critical buckling load and buckling mode shapes, as well as postbuckling respon ses.