Micromechanical damage of FRC: Modeling and parametric analyses

In the present paper the nonlinear response of fiber reinforced concrete (FRC) material is investigated in the framework of the micromechanics of heterogeneous materials. In fact, FRC is regarded as a composite with fibers embedded into a concrete matrix. A 2D unit cell, with a single fiber, subjected to tensile strain in the fiber direction is considered. To model the progressive FRC damage, i.e. the fiber debonding and pull-out and the concrete cracking, fibermatrix elastoplastic and matrix-matrix damaging interfaces are introduced. Then, numerical analyses are performed to investigate the interaction between the fiber debonding and the crack propagation, and to derive the overall macroscopic response of the FRC composite material. The numerical results obtained allow to verify the accurancy of the model adopted for the computation and its limits. Furthermore, several different analyses are performed in order to investigate on the role played by the fundamental material and geometric parameters