Simulation du comportement d’une structure soumise à différente type de défaut (fissure/entaille)

Abstract

Fracture mechanics is a fundamental discipline in mechanical engineering that focuses on the behavior of materials containing defects or discontinuities. Its primary objective is to understand the mechanisms of crack initiation and propagation in order to prevent sudden structural failures and enhance the reliability of engineering components during service. This work first presents the theoretical foundations of fracture mechanics, including the different fracture modes, the Stress Intensity Factor (K), and the development of the plastic zone near the crack tip. It also reviews the main analytical approaches used

for notch assessment, such as Pluvinage’s volumetric approach, the equivalent crack concept, and the Creager–Paris formulation. The study then examines the nature and classification of structural defects, including cracks, notches, and corrosion damage, while discussing the maintenance and repair techniques commonly employed in industry. Particular attention is given to bonded composite patch repair, a widely adopted solution in the aerospace sector for restoring structural integrity and extending service life. Finally, a three-dimensional numerical investigation is carried out using the Abaqus software package to evaluate the effectiveness of a Boron/Epoxy composite patch in reinforcing an aluminum plate containing either a crack or a notch. The study also addresses the simulation of crack growth and fracture path propagation using the eXtended Finite Element Method (XFEM), providing a deeper understanding of the behavior and damage tolerance of repaired structures.