Mixed-mode I + II fatigue/fracture characterization of composite bonded joints using the Single-Leg Bending test

In this work, fatigue/fracture characterization of composite bonded joints is performed using the Single-Leg Bending (SLB) test. The SLB test provides a mixed-mode I + II loading with a fixed mode mixity. Specimens of carbon fibre reinforced epoxy bonded with a ductile epoxy adhesive were tested considering two load levels. The applicability of the Paris-law establishing a relationship between the fatigue crack growth rate and the variation of the energy release rate was analyzed. An equivalent crack method was used to overcome the difficulties associated to crack monitoring during the fatigue tests. Consistent results were obtained for the lower load level, thus proving the adequacy of the SLB test concerning fatigue/fracture characterization of bonded joints.