Prediction of the mechanical response of polycrystalline ceramics containing metallic intergranular layers under uniaxial tension

The present contribution focuses on the problem of the mechanical response of a polycrystalline ceramic material containing intergranular layers. The internal structure of the material was modelled using eight-noded isotropic hexagonal finite elements to represent grains and interfaces. Two kinds of the material were analysed numerically. Both were made up of elastic grains, but in the first case the interface layers were elastic and had different properties in comparison to the grains. In the second case, the interphase had visco-plastic properties. The paper considers the influence of the initial heterogeneity of the material on the stress and displacement distribution inside the polycrystalline material subjected to uniaxial tension. One can observe local stress concentrations at the so-called “triple points” and on the surface of the material. These can act as cracks initiators. Additionally, the influence of the viscosity parameter of the interface material was investigated.