Edge Debonding Prediction in Beams Strengthened by FRP Composite Plates

Edge debonding initiation and propagation in beams strengthened withfiber–reinforced composite plates is here studied. The structural system is composedby three physical components, namely the beam, the adhesive layer and the bondedplate, which are modeled by one or several first–order shear deformable layers accordingto a multi–layer formulation, wherein both strong and weak interface constitutiverelations are introduced to model interfaces. Debonding onset is predictedwith the aid of a mixed mode coupled stress and energetic criterion, and propagationin different locations across the adhesive thickness is studied by using a mixedmode fracture criterion. The proposed models are implemented according to the 1Dfinite element technique, allowing accurate evaluation of interlaminar stresses andfracture energies.