Quasi-static and fatigue analyses of aluminium structures repaired by CFRP patch bonding

In this work, quasi-static and fatigue analyses of the three most common adhesive repair geometries were performed considering composite patches and aluminium as parent material. Experimental three-point bending tests were accomplished on single-strap, double-strap and scarf repairs in order to obtain the load-displacement curves for quasi-static analysis, and compliance versus number of cycles curves for the fatigue studies. The main goals are to identify the static strength and fatigue lives for each type of adhesive repair. In addition, progressive damage analyses that rely on two cohesive zone models appropriate for quasi-static and high-cycle fatigue under mixed-mode I+II loading were performed. These models allow the simulation of damage initiation and propagation in the repairs under quasi-static and fatigue loading. It was found that both models are able to replicate the fundamental trends observed experimentally, thus establishing their effectiveness.