Compressive behavior of rectangular composite laminates with multiple circular delaminations

Abstract

Compressive behavior of composite laminates with multiple circular delaminations is studied analytically and experimentally. In the experiment, two types of laminates with a conventional and toughened epoxy resin are prepared. Embedded delaminations are introduced at regular intervals in the thickness direction. The loading edges are fixed and the side edges simply supported. In the analysis, a classical plate theory is used and the governing equation is derived through the Rayleigh-Ritz method. The buckling equation is obtained by neglecting higher order terms. Owing to the assumption of equal spacing for multiple delaminations, the buckling modes of the lowest buckling load are physically admissible and the contact problem need not be considered. The analytical buckling loads agree well with the experimental results. The effects of size and number of the delaminations on the buckling and failure load are parametrically studied. The buckling loads do not depend on the toughness of the matrix resin, although the failure strength depends on the toughness of the matrix resin. (Author)