A coupled virtual element-interface model for analysis of fracture propagation in polycrystalline composites

This paper proposes a coupled virtual element-interface finite element model for the analysis of the fracture propagation in polycrystalline composites with random microstructure. The key idea is to discretize each crystal, also referred to as grain, with a single low order virtual element with elastic constitutive response, and describe the interaction between grains by means of damaging and frictional zero-thickness interface finite elements. Thus, the typical intergranular crack growth is modeled by avoiding refined finite element grain discretizations with relevant computational cost saving. Results of numerical simulations are presented and discussed. First, some benchmarks show the reliability of the proposed modeling strategy. Then, the response of Alumina/Zirconia representative volume elements, whose size is selected on the basis of results of a statistical homogenization procedure tailored for random composites, is investigated by analyzing the effect of the variation of the metallic phase volume fraction and the shape of grains composing the microstructure.