Evaluation of the effects of stress concentrations on plates using granular micromechanics

•Numerical implementation of a granular micromechanics model into Abaqus/Explicit.•Determination of the model parameters from grains’ properties and grain-pair interactions.•Effect of the orientation of the inter-granular forces compared to the direction of the applied loading.•Modeling the effects of stress concentrators on the failure of granular-made plates under uniaxial and biaxial solicitations. This work is dedicated to the study of the effect of stress concentrations in plates induced by notches and holes using a Granular Micromechanics (GM) model. To this end, three structural configurations were analyzed: an intact plate, a plate with a central circular hole, and a plate with two notches. For comparison of the mechanical response of these plates, the radii of the hole and the notches are taken the same. The material behavior of the plates is described through the multiscale GM constitutive law. The equations of this model are formulated based on the mechanical properties of the grains, the grain-pair interactions and the relative movement of the grains. So the identification of the material parameters needs only the determination of the grains’ properties and grain-pair interactions. This micromechanics-based model has been implemented into the finite element code Abaqus/Explicit through a Vectorized User MATerial (VUMAT) subroutine. The model is applied to study the plates under uniaxial and biaxial loadings. This study aims to assess the pertinence of applying the GM model to structural analysis and show the influence of the two geometrical imperfections on the overall behavior of the structure. It has been found that the model can describe the behavior of plates under tension and compression loadings. Moreover, the effects of a hole and notches on the behavior and failure of the granular-made plates are captured.