Predicting the fracture strength of ceramic materials using the theory of critical distances

This paper describes a critical distance theory which uses local stress field information to predict the effect of stress concentrations. The approach was originally developed for predicting fatigue limits in metallic materials; this paper shows that it is also capable of predicting fracture strength in ceramics containing notches, long cracks and short cracks. The method is very easy to use, especially in conjunction with finite element analysis. It is proposed that it be given the name the theory of critical distances (TCD). It is a continuum mechanics approach, similar to linear elastic fracture mechanics (LEFM), but of more general applicability.