Advanced damage prediction in notched plates reinforced with Graded composite patches: Integrating XFEM-CZM and fiber-matrix coupling laws using Functionally Graded Materials

This study introduces a novel approach to reinforcing notched aluminum plates using functionally graded composites (FGCs). By integrating volume fraction principles of Functionally Graded Materials (FGMs) into fiber-matrix mixture laws, we propose an advanced patch reinforcement strategy. The research employs the Cohesive Zone Model (CZM) and Extended Finite Element Method (XFEM) in ABAQUS to simulate patch debonding, crack initiation, and propagation. We compare linearly graded and FGM patches against non-graded counterparts, demonstrating superior load distribution and damage tolerance of graded composites. Three gradation concepts are explored: C-1 (peak fiber density at mid-thickness), C-2 (increased fiber density near patch edge), and C-3 (highest fiber density adjacent to the adhesive joint). Results reveal a critical interplay between adhesive debonding and crack propagation in the aluminum substrate. The study highlights the efficacy of graded composite patches in mitigating damage and offers significant insights into advanced reinforcement techniques for enhanced structural durability and reliability in engineering applications.