Comportement élastique d’une fissure réparée sous chargement de traction biaxial pour une plaque aéronautique fissurée.

Abstract

This thesis investigates the elastic behavior of a cracked aluminum plate (2024-T3 alloy) subjected to different types of loading (uniaxial and biaxial), with the objective of analyzing and enhancing its mechanical performance through repair solutions. The finite element method, implemented using Abaqus software, was used to simulate the fracture behavior and evaluate the stress intensity factors (KI, KII, KIII) along with the T-stress. Two repair strategies were studied: the first involved a Boron/Epoxy composite patch bonded to the plate with FM73 adhesive; the second used a functionally graded material (FGM) patch made of Ni–Al2O3, with five different Young's modulus distribution profiles. Numerical results showed that biaxial loading significantly increases mixed-mode crack propagation and stress concentrations. Compared to the conventional composite patch, FGM-based patches provided a better reduction of stress intensity factors and a more uniform distribution of stresses along the crack front. This study demonstrates the potential of FGM patches to improve the durability and reliability of repaired aerospace structures subjected to multiaxial stresses, and provides a numerical framework for further developments in smart repair technologies.