This paper focuses on the prediction of edge debonding for a concrete beam retrofitted with a fiber-reinforced polymer plate. This failure mechanism, also known in the literature as plate- end debonding, stems from the concentration of interfacial stresses arising at…
This paper focuses on the prediction of edge debonding for a concrete beam retrofitted with a fiber-reinforced polymer plate. This failure mechanism, also known in the literature as plate- end debonding, stems from the concentration of interfacial stresses arising at the termination of the strengthening plate. Early models of edge debonding adopted failure criteria based on interfacial stresses. However, due to the typically catastrophic nature of this failure mechanism, approaches based on linear elastic fracture mechanics (LEFM) are becoming increasingly established. In this paper, the problem is addressed by means of the cohesive crack model. This model is able to bridge the gap between the stress- and the energy-based approaches and nevertheless has been used in a very limited number of analytical studies to date. Based on a cohesive interface law with linear softening, closed-form solutions for the interfacial stresses and the load-displacement curves, as well as for the ultimate load, are derived. A parametric analysis shows that for sufficiently brittle interfaces both snap-back and snap-through instabilities may arise. As the interface ductility increases, the snap-back disappears and finally a monotonic load-displacement curve is obtained. LEFM is shown to provide unconservative estimates, which justifies the need for the proposed approach.