Numerical analysis of composite patch repairs on damaged plates with optimized geometric modifications for improved fracture strength
Salma Aminallah, K. Madani, M. Benyettou, M. S. N. Boussahra, M. W. Harmel, R.D.S.G. Campilho
Abstract
The effectiveness of patch bonding repair depends on the mechanical and geometric properties of the adhesive and patch, which ensure proper load transfer without damaging the adhesive layer. Maintaining an optimal stiffness ratio between the plate and patch is crucial, often requiring adjustments to the stacking sequence or patch geometry. While various geometric modifications have been proposed to enhance structural durability, few studies have explored modifications to the damaged metal plate itself. This study presents a numerical analysis of composite patch repairs on damaged aluminum plates, incorporating geometric modifications to improve fracture strength. The investigation employs finite element modeling to evaluate the impact of material removal at the damaged area on fracture behavior, with and without repair. Key parameters analyzed include J-integral values at the crack tip, Von Mises stresses in the adhesive layer, patch geometry, and plate thickness variations. Results demonstrate that a 0.2 mm material removal does not induce excessive stress concentrations, ensuring structural integrity under low loads. When reinforced with a composite patch, even under higher loads, the modified plate exhibits superior strength compared to an unmodified one. Optimizing adhesive properties and plate thickness further increases the repair performance, significantly reducing J-integral values by mitigating bending effects caused by the asymmetric repair.