Numerical study of the bond behavior of DMF systems

New materials and techniques continuously enrich the family of fiber reinforced polymer (FRP) systems to use for retrofit interventions of existing masonry constructions. Recently, the deep mounted flexible (DMF) technique, consisting of the execution of deep grooves in the masonry where FRP strips are placed by using flexible adhesives, have been proposed. The studies available in literature show the potentialities of this technique and its advantages with respect to traditional techniques. At the same time, these studies also emphasize a behavior with specific features influencing the performance of DMF systems which need to be investigated. Aim of the present paper is to propose numerical approaches for the study of the bond behavior of DMF systems. In particular, it is presented both an approach based on the solution of the system of differential equations governing the shear stress transfer mechanism (ODE-DMF), and a simplified finite element schematization (FEM-DMF). Both the approaches are implemented in different computer codes and validated toward case studies derived from literature. The comparison with the experimental tests shows the ability of the proposed modeling approaches to reproduce the experimental response of the examined specimens by underlying features related to the shear stress transfer mechanism between the reinforcement placed in the groove and the surrounding masonry.