Fracture behaviour of damaged wood beams repaired with an adhesively-bonded composite patch

An experimental and numerical study is presented concerning the fracture behaviour of scaled specimens of wood beams repaired with a carbon–epoxy patch under four-point bending. In this work, a numerical technique is proposed to simulate the fracture behaviour of these repairs, which includes the possibility of cohesive failure in the adhesive layer, failure within the wood beam in different planes, and interlaminar failure of the patch. This methodology uses the finite element method and cohesive damage modelling, whose properties for the different fractures were obtained either by an inverse method or from the literature. The experiments allowed the validation of this methodology, in terms of failure mode, elastic stiffness and maximum load of the repairs. The numerical results showed that the proposed technique is adequate to predict the behaviour of these repairs.