Modeling Damage Propagation in Composite Plates with Embedded Delamination under Compressive Load

A numerical procedure aimed at simulating the structural behavior of delaminated composite plates under compressive load, is developed and presented in this article. Although delamination buckling and growth have been widely studied in the literature, in this article the effect of fiber-matrix failure on the buckling behavior of a delaminated structure up to final failure is investigated in detail. A geometrically non linear finite element (FE) approach is adopted for elastic instability simulation, the modified virtual crack closure technique (MVCCT) is used for the energy release rate (ERR) evaluation at the delamination front and fracture mechanics based progressive damage approach is introduced for the simulation of fiber-matrix damage onset and evolution. Comparisons of numerical results with existing experimental data on composite panels with an embedded circular delamination under compressive load, are presented for preliminary validation purposes. Furthermore, the influence of the different failure mechanisms on the compressive behavior of delaminated composite plates is assessed, by comparing numerical results obtained with models characterized by different degrees of complexity. Finally, results of a limited sensitivity analysis are shown, pointing out the influence of some key parameters characteristics of the adopted numerical approach on the accuracy of numerical simulations.