A New Method to Investigate the Progressive Damage of Imperfect Composite Plates Under In-Plane Compressive Load

Numerous studies have been conducted for failure criteria of fiber reinforced composites. The aim of this study is to present a new computational and mathematical method to analyze the progressive damage and failure behavior of composite plates containing initial geometric imperfections under uniaxial in-plane compression load. A new methodology is presented based on collocation method in which the interested domain is discretized with Legendre-Gauss-Lobatto nodes. In order to avoid an excessive number of nodes, an appropriate weight coefficient is considered for each node. The method is based on the first order shear deformation theory and small displacement theory. Several failure criteria, including Maximum stress, Hashin and Tsai-Hill, are used to predict the failure mechanisms. The stiffness degradation is carried out by instantaneous and complete ply degradation model. Two different types of boundary conditions are considered in this study. The effects of thickness, initial imperfections, and boundary conditions are studied, as well. The results are compared with the previously published data. It is found that the boundary conditions have significant effects on the ultimate strength of imperfect composite plates.