Computational Modeling of FRP Reinforced Cementitious Beams

In the present paper, a one-dimensional elastoplastic-damage model for the analysis of the mechanical response of beams constituted by cementitious materials, i.e., concrete or masonry, strengthened by fiber reinforced polymers (FRP), is developed. The analysis is performed for a typical section, representing an elementary part of beam characterized by the finite length, defined as the distance between two fractures. A thermodynamically consistent model is proposed; it takes into account the different behavior in tension and in compression of the cohesive materials. The governing equations are derived and a numerical procedure is developed. It is based on thearc-length method, withinan implicit Euler algorithm for the time integration. An accurate choice of the control parameters is performed. The finite step nonlinear problem is solved adopting a Newton-Raphson scheme within a predictor-corrector procedure. Some numerical examples are developed in order to analyze the non trivial axial and bending behavior of reinforced concrete and masonry beams and to assess the efficiency of the proposed pmedure. Comparisons with analytical solutions are reported.