MICROMECHANICAL ANALYSIS OF UNREINFORCED AND REINFORCED MASONRY ARCHES

This work analyzes the in-plane response of unreinforced and reinforced masonry arches by adopting micromechanical finite element (FE) models. These allow to describe onset and evolution of degrading mechanisms until failure, including the accurate characterization of the pre- and post-peak behavior. Two different models are adopted: the first considers each masonry component, brick and mortar, as continuous material discretized with quadrilateral FEs; the second connects properly resized bricks through interfaces representing both mortar and mortar-units interaction. Linear elastic behavior is assumed for bricks, whereas a cou- pled damage-friction constitutive law is adopted for mortar to account for typical arch collapse mechanisms involving flexural hinges and shear sliding. As concerns the modeling of the rein- forcements, these are considered as truss elements with bilinear response in tension. In such a way the debonding and delamination phenomena are accounted in a simplified way. Results obtained with the proposed models are validated through comparison with exper- imental data and solutions obtained from other numerical approaches. It emerges that the response of both the unreinforced and reinforced elements are satisfactorily described, as well as the positive effect of the introduction of the reinforcement on the collapse load and failure mechanism.