Enhanced numerical modelling of damage and repair in notched 2024-T3 aluminum plates using XFEM, CZM, and VCCT
Safaa Chahrazad Djebbar, M. Benyettou, K. Madani, M. W. Harmel, M. Belhouari, Mohamed Elajrami, X. Feaugas, R.D.S.G. Campilho
Abstract
Structural defects that present a high concentration of stresses, such as V-notches, considerably weaken metallic components. These geometric defects can initiate cracks in the structures even under low loading which can propagate rapidly causing their deterioration. These defects can be repaired using several methods. Indeed, the repair technique, such as the bonding of composite patches offers an effective solution to extend the service life of these damaged structures. For this purpose, the mechanical behavior of a damaged 2024-T3 aluminum plate with double lateral V-shaped notches, repaired and not repaired by bonded carbon/epoxy composite patch, was analyzed. Experimental tensile tests on damaged and repaired plates by single and double patches were carried out to demonstrate the performance of the repair technique. The extended finite element method (XFEM) is used to simulate the initiation and propagation of damage in the plate, while the adhesive detachment is modeled using the cohesive zone technique (CZM) and then through the virtual crack closure technique (VCCT). The numerical results, compared with the experimental tensile test results, demonstrated a good agreement. Consequently, the comparative analysis of XFEM + CZM and XFEM + VCCT techniques showed that these two combinations can provide good results by optimizing the choice of density and types of mesh elements and that the damage of the plate, as well as the adhesive, can be monitored at different load levels.