AN ACCUMULATIVE DAMAGE MODEL FOR TENSILE AND SHEAR FAILURES OF LAMINATED COMPOSITE PLATES

A progressive failure model was developed for predicting the accumulated damage and the effect of such damage on the in-plane response of laminated composite plates subjected to tensile and shear loads. Internal damage in composites induced by matrix cracking under in-plane tensile and shear loads was the primary concern. Free edge-induced damage was not considered. The model assumes that the damage would accumulate uniformly in a laminate when it is subjected to uniformly distributed loads. The progressive failure model consists of two parts: constitutive modeling and damage accumulation prediction. Constitutive equations were established for relating the effective material properties of a damaged ply in a laminate to the extent of damage. Damage accumulation criteria were proposed by modifying the existing failure criteria for estimating the accumulated damage as a function of the applied loads. A finite element analysis, designated as ''PDCOMP,'' was developed based on the model. In order to verify the model, predictions from the analysis were compared with the experimental data available in the literature. Additional tests were also conducted to substantiate the model. Overall, the predictions agreed with the data quite well.