Modelling of micromechanical fracture for ceramic composites through the Voronoi Cell Finite Element approach

In this work the micromechanical behaviour of ceramic composites has been investigated through a non-linear hybrid finite element approach. The Voronoi Cell Finite Element Method has been extended in order to investigate the damage tolerant behaviour at the microstructural length scale in homogeneous ceramics and Alumina/Zirconia composites. A criterion based on the average normal tensile stress acting on grain boundary has been assumed as the condition for the nucleation and propagation of intergranular fractures. The paper presents the study of the effects of the residual stresses and gradient mechanical properties on the near-surface stress field arising in contact problems.