Simulation of mechanical behaviour of composite bonded joints containing strip defects

The objective of this work is to evaluate the influence of strip defects on the mechanical behaviour of composite bonded joints. Experimental tests were performed using carbon-epoxy single-lap bonded joints. Numerical simulations included interface finite elements and a mixed-mode damage model based on the indirect use of fracture mechanics. The interface finite elements allow the calculation of stresses at the adherend–adhesive interfaces and the damage model allows the simulation of damage initiation and growth. The application of the model to a single-lap joint is presented. The influence of a defect on the stress fields, joint strength and type of failure was evaluated. It was verified that specific strength of the joints was not affected by the size of the defect. The numerical results showed good agreement with the experimental ones.