Numerical Investigation on the Size Effect of a WC/Co 3D Representative Volume Element Based on the Homogenized Elastoplastic Response and Fracture Energy Dissipation

Tungsten carbide-cobalt (WC/Co) is a two phase material composed of two distinct interpenetrating phases having different mechanical properties. The hard and brittle WC phase behaves elastically whereas the Co phase demonstrates an elasto-plastic response. In order to predict the global behavior of the material from its microscopic constitution, the representative volume element (RVE) model has to satisfy basic requirement of a certain size. Moreover the homogenized response of the RYE has to be characterized with respect to the macroscopic mechanical property of interest. Taking into consideration such phenomenon the current study investigates the size of 3D RVEs that are adequate to reflect the global elasto-plastic response and the fracture (damage) energy dissipation. The results of the homogenized elasto-plastic responses were compared to a macroscopic experimental stress-strain curve and the fracture energy dissipation was validated by a convergence study. It has been observed from the numerical simulation that, despite the randomness of the structure, the development of volume averaged elastic potential, plastic and as well as the fracture energy dissipation would stabilize with the increasing size of the RVE.