On the problem of cracking in 2-phase ceramic matrix composite materials

Abstract

The aim of the paper is to present a theoretical analysis of phenomena occurring in the 2-phase ceramic composite with the gradual degradation of the material properties under the uniaxial tension process. Ceramic composite materials have a nonlinear and complex overall response to applied loads. It is caused by the following factors: existence of an inital porosity, development of limited plasticity, different phases and internal microdefects. These microdefects cause stress concentrations and locally change the state of stress, which results in the development of mesocracks leading to macrocracks. In this contribution, a multiscale approach was applied in modelling of such material response to depict phenomena at micro- mesoand macro-scales. In experiments it was shown that defects developed mainly intergranularly what resulted in inhomogeneity and induced anisotropy of the material.