Analytical and finite element modeling simulation of buckling and postbuckling of delaminated orthotropic plates

Delamination is one of the most common failure modes of laminated composite materials, and can be caused by manufacturing defects or impact loading. Under compression, a delaminated composite plate may buckle and tend to enlarge the delaminated area, which can lead to loss of global structural stability. This paper presents the elastic buckling and postbuckling analysis of an axially loaded beam-plate with an across-the width delamination, located at a given depth below the upper surface of the plate. The analysis is done by considering a layered orthotropic plate containing through width delamination, subjected to in-plane compression. The problem is analyzed by two approaches: (i) A simple analytical model for determining strain energy release rate is obtained using integral transform approach; (ii) A finite element representation of the problem is modeled and analyzed using MSC/NASTRAN and the buckling load is calculated