Progressive buckling of a simply supported delaminated orthotropic rectangular composite plate

In this work we analyse the buckling process of composite plates with trough-the-width delamination and straight crack front applying uniaxial compression. Local, global and mixed mode buckling cases are considered. The novel part of this work is that the distribution of the resulting in-plane forces is taken into account for the analysis of the buckling of the delaminated plate portions. For determining the behaviour of the delaminated plate with respect to the external compression, first an analytical method is given for determining the global critical loads. Second the local critical forces are determined using a finite element model. For this analysis a semi-discrete element was developed for the delaminated plate portions. The analysis was carried out using the method of harmonic balance because of the distribution of the in-plane forces along the delamination front. The buckling process of the plate with respect to the axial compression is determined from a displacement controlled model.