Damaging of frcm composites through a micro-scale numerical approach

Aim of this paper is to proposed a micro-scale numerical approach for the evaluation of the mechanical behavior of Fiber Reinforced Cementitious Mortar (FRCM) composites. As a matter of fact, the FRCM constitutive behavior is affected by micro-mechanisms, such as the cracking of the mortar and the slippage of the fibers within the mortar. The repetitive structural geometry of the FRCMs, due to the presence of the mesh grid, allows to identify a representative unit cell. This element is made by different constituent materials, i.e. fiber and mortar, and composed by three layers, i.e. two external layers of mortar and one inner layer made with fibers and mortar. In the framework of 2D plane stress state, the numerical approach consists in modeling the constituents as linear elastic materials and accounting for the material non-linearities through the implementation of suitable interface elements. In the interface model, the damage, the friction effects and the unilateral contact are taken into account. This numerical approach is used for reproducing the tensile behavior of the FRCM composites. It is successfully validated with available experimental results and a parameter sensitivity analysis is performed.