Experimental tests and numerical modeling of reinforced masonry arches

The present paper deals with the experimental campaign and the numerical modeling of reinforced masonry arches strengthened with fiber reinforced plastic (FRP) strips. The mechanical properties of masonry material constituents, clay bricks and mixed mortar, are determined through laboratory tests. The experimental response of unreinforced and reinforced arches is investigated. A nonlinear elastic constitutive law for the masonry material is proposed; in particular, the stress–strain relationship is characterized by no-tensile strength and by a quadratic response with exponential post-peak softening in compression. The FRP reinforcement is modeled as a no-compressive material with uniaxial linear elastic constitutive relationship in tension, until a limit strength response characterized by brittle collapse. A beam finite element is developed and a numerical procedure, based on the Newton–Raphson method, is implemented to solve the nonlinear structural problem. The question of the proper setting of the material parameters to consider in the numerical analyses is addressed. Results obtained using the numerical procedure are compared with the experimental ones in order to assess the ability of the proposed procedure and of the model in predicting the failure mechanisms and the global structural response.