Micromechanics based damage model for predicting compression behavior of polymer concretes

摘要

In this study, the compressive behavior of polymer concrete (PC) is investigated using micromechanics-based representative volume element (RVE) concept. The RVE is composed of silica aggregates and epoxy matrix. The aggregate and matrix are modeled as linear elastic and elasto-plastic material, respectively. The interface between aggregates and matrix is modeled by employing a bilinear traction-separation law and its parameters are computed from Mohr-Coulomb failure criterion. RVE is modeled in Digimat software and imported into ABAQUS for damage analysis. Three types of boundary conditions, i.e., Dirichlet, periodic, and mixed are considered in the RVE modeling. The influences of aggregates shape, distribution, volume fraction, and interfacial parameters on the overall compressive behavior of PC are studied under uniaxial compression loading. In order to assess the micromechanical RVE model, standard cylindrical specimens of PC are manufactured and tested under uniaxial compression. Comparison of numerical and experimental results shows that: 1) the more the interfacial strength and fracture energy increases, the more the compressive strength of PC increases; 2) the compressive behavior of PC is highly dependent on aggregate volume fraction and distribution in comparison to aggregate shape, 3) the model has appropriate accuracy in predicting the compressive behavior of PC.