A probabilistic model for the scale effect on fracture toughness of structural ceramics

The fracture toughness of polycrystalline ceramics used to present the scale effect as well as statistical distribution. It is believed that both (scale effect and scatter) must be associated with the heterogeneity of materials. However, no generally accepted theory has been established so far. Using statistical approach, a probabilistic modelling for the fracture toughness which describes the scale effect was attempted in this paper. Weibull distribution of specific fracture energy (SFE) at local area and Griffith criterion are jointly applied to the model. Finally, the fracture toughness scale dependence of ASTM E399 standard specimens was investigated by the newly developed model.