Progressive failure analysis of CFRP laminate with interacting holes under compressive loading

Composite structures such as hull of a ship and wings of aircraft are subjected to compressive loading. The behavior and strength of carbon fiber-reinforced polymer (CFRP) panels subjected to tensile loading has been studied rigorously by various researchers, whereas compressive behavior is not well addressed. In this study, behavior of CFRP panel with multiple interacting holes of various configurations (1H, 2HL, 2HT, and 2HD) under compressive loading is studied. A three-dimensional finite element-based progressive failure analysis (PFA) is used to model the damage progression in CFRP laminates. Damage detection is carried out using both Hashin’s failure and Ye’s-delamination criterions. Using these failure criterions, failure and post failure behavior of CFRP laminate with cutouts are predicted. The material is assumed to behave as linear elastic until final failure. Sudden degradation rule of material property is employed and subsequently PFA is carried out successively. Using digital image correlation (DIC) technique, whole field surface strain is obtained experimentally and is used for validating finite element analysis (FEA) model. Load–deflection behavior as well as path of damage progression is predicted by both PFA simulation and experiment. They are found to be in good agreement thereby confirming the accuracy of PFA implementation. Among all the configurations, one with two holes along the longitudinal direction (2HL) is recommended for design application as it exhibits low stress concentration factor and sustains higher initiation and final failure load