Stress Analysis of Reinforced Masonry Arches

The paper deals with the modeling and the analysis of masonry arches reinforced with FRP materials. A nonlinear elastic model for the masonry material, characterized by no tensile capacity and limited strength in compression, is proposed; the FRP is modeled as a linear elastic material with brittle failure, considering a perfect adhesion between the masonry and the FRP reinforcement. A novel numerical procedure based on the stress approach of the structural problem, i.e. on the minimization of the complementary energy, is developed within a dual formulation of the arc-length continuation method. The proposed model and the developed numerical procedure are implemented in a computer code. Moreover, a new post computation technique of the stresses at the FRP-masonry interface, based on a micromechanical analysis that takes into account the heterogeneity of the masonry material, is proposed. Numerical applications are developed to assess the model effectiveness and the efficiency of the numerical procedure. The results obtained using the proposed model and implemented procedure are put in comparison with the ones carried out considering an elasto-plastic masonry model implemented in a finite element procedure; finally, a comparison between numerical and experimental results is provided.