Virtual elements and zero thickness interface-based approach for fracture analysis of heterogeneous materials

A novel procedure for analyzing fracture processes in quasi-brittle materials and consisting in combining the discrete crack approach by means of interface elements with the Virtual Element Method is proposed and developed in this work. In particular, the proposed procedure is used in the simulation of non-linear mechanical response and cracking of cement-based composites at the mesoscopic level of observation. Thereby three components are recognized: mortar, coarse aggregates and mortar-aggregate interfaces. In this regard VEM constitutes a powerful and efficient tool to represent the complex geometries of the inclusions in composite materials, such as coarse aggregates in concrete. Actually, patches with any number of edges (not necessarily convex), hanging nodes, flat angles, collapsing nodes, etc., can be easily handled in the VEM framework while retaining the same approximation properties of FEM. On the other hand, classical zero-thickness interface elements (IEs) are employed for modeling stress-crack opening processes. A series of numerical results, not only at the mesoscopic but also at the macroscopic level of observation, are presented to demonstrate the soundness and capabilities of the proposed approach based on combinations of VEM and IEs.