Advanced Prediction and Analysis of Delamination Failure in Graphite-Reinforced Epoxy Composites Using VCCT-Based Finite Element Modelling Techniques

The applications of graphite-reinforced composite laminates have gained significant importance since the last century and remain a highly attractive field due to their widespread and versatile applications. Among the various failure modes, delamination-defined as the separation of layers within the composite structure-stands out as the most common and critical type of failure in these materials. In this study, the mode I interlaminar fracture energy was predicted using the virtual crack closure technique (VCCT) integrated with a finite element model (FEM), applied to a double cantilever beam (DCB) specimen. Additionally, a straightforward analytical model was developed to calculate the critical fracture energy in mode I. The analytical model used the material strength and stiffness. The results demonstrated strong agreement with experimental data, with a margin of error as low as 5%, highlighting the accuracy and reliability of the proposed methods.