Intermediate flexural detachment in FRP-plated concrete beams through a 3D mechanism-based regularized eXtended Finite Element Method

The present study focuses on a three-dimensional computational methodology aimed at modeling the detachment of FRP plates from reinforced concrete beams. Most finite element models introduce FRP-to-concrete bondslip laws difficult to be derived, while simulate the cracks in the concrete with smeared crack models. Conversely, the proposed approach is based on the regularized eXtended Finite Element Method with a mechanism-based detachment. It does not require bond-slip laws, and makes use of standard material parameters. The introduction of a regularization length and the adoption of a proper mechanical framework lead to an accurate and predictive methodology for smooth simulations of the FRP-detachment process. In the currently investigated range of thicknesses and widths of the FRP plate, the proposed methodology discloses the dominance of detachment by intermediate flexural cracks.