A model for predicting the mixed-mode fatigue crack growth in a bonded joint

Bonded joints are highly sensitive to the presence of defects and to the degradation phenomena, and this aspect represents the primary obstacle to their use in different structural engineering applications. Delamination in a bonded joint represents, in fact, one of the primary, most common and insidious causes of damage. In this paper, a numerical-experimental study on the crack propagation along the adhesive layer of a bonded joint specimen is carried out. Experimental study is focused on the evaluation of the damage modalities of a bonded joint when the specimens are subject to fatigue load. Experimental tests are compared with the results of several numerical analysis performed in ANSYS environment. A crack growth model is implemented in the finite element method solver and allows the simulation of the progressive delamination process. Comparison between numerical results and experimental tests allows to identify the descriptive numerical parameters of fatigue crack propagation, which may be used in the structures design.