Effect of patch geometry on the structural performance of damaged plates in bonded patch repairs techniques using a combination of XFEM and CZM techniques
M. W. Harmel, Madani Kouider, M. Benyettou, M. S. N. Boussahra, Aminallah Salma, K. Zouggar, R.D.S.G. Campilho
Abstract
The analysis presented in this work aims to propose two repair patch shapes to reinforce a notched aluminum plate through the Adekit A-140 adhesive. Two different carbon fiber reinforced polymer (CFRP) patch geometries, X-shaped and butterfly-shaped, were analyzed to evaluate their impact on the repair tensile response, in the form of load-displacement curves. A factorial design of experiment (DOE) was implemented to systematically examine the effects of the key geometric parameters of the two patches based on a comparison with a square-shaped patch. Once the experimental design was established, a numerical finite element method (FEM) model of the repaired and unrepaired plate was developed and validated using experimental results. The analysis considers the use of the combination of two techniques, cohesive zone modeling (CZM) and extended finite element method (XFEM), to simulate crack propagation and the failure mechanisms in the plate and adhesive. The results showed that the patch geometry can be optimized to ensure material savings up to 4% and lighten the weight, while ensuring the load transfer, strength, and global repair efficiency. Furthermore, the results confirm that various patch geometries can be effectively used to achieve the required mechanical performance comparable to the standard square patch repair, providing higher flexibility in repair design while preserving structural integrity.