PSI - Issue 38

244 Hamza Abbad El Andaloussi et al. / Procedia Structural Integrity 38 (2022) 238–250 Hamza Abbad El Andaloussi, Luc Mouton, Firas Sayed Ahmad, Xabier Errotabehere, Stéphanie Mahérault-Mougin, Stéphane Paboeuf/ Structural Integrity Procedia 00 (2021) 000 – 000 7

Figure 4: Number of cycles at failure for each of the tested specimen at several ultimate tensile capacity load levels

Additionally, the fractography analysis of the debonded part of the single-strap specimens is performed. For all the 25 tested specimens, the failure type is adhesive and occurs at the interface between the steel substrate and the adhesive (so- called “bondline”). Figure 5 presents the debonded area:

Figure 5 Debonded single strap after fatigue test – Top view

This interfacial failure mode is repeatable as it is observed for all the 25 tested samples. As already observed previously for quasi-static loadings Erreur ! Source du renvoi introuvable. , these test results also demonstrate that the most critical part of the reinforcement in terms of tensile fatigue loads is the interface between the substrate and the adhesive. 4. Numerical analysis The purpose of the numerical analysis is to determine the acting interfacial stresses (peel and shear) at the bondline corresponding to each of the load ranges tested experimentally. Numerical Model The single-strap specimens tested during the fatigue campaign are modelled under ABAQUS FEA software with the geometry presented in Figure 6: