Effect of interface model parameters on the numerical response of a FE model for predicting the FRCM-to-masonry bond

Fabric-reinforced cementitious matrix (FRCM) materials are increasingly common for strengthening existing masonry structures. The constitutive behaviour of these materials is complex to model due to the inner complex mechanisms that develop in composite mechanics, such as stress transfer between matrix and fabric, mortar cracking, friction at the matrix-to-fabric interface, and bonding with the substrate. This paper aims to address these phenomena by presenting a numerical approach able to predict the bond behaviour of FRCM-to-masonry systems through the use of simple truss elements and nonlinear springs to simulate the fabric-to-matrix and composite-to-substrate interactions. The model was implemented in an open-source environment and allowed direct sensitivity analysis to assess the role of the constitutive variables. The comparisons between the results of the numerical approach and experimental responses show that the proposed methodology is an effective and easy tool to predict the mechanical behaviour of FRCM composites, with a reduced computational effort.