Model for fracture of ceramics based on the probability distribution of fracture toughness

Generally speaking, the scatter of fracture strength depends on the defect size only. However, we experience that the fracture toughness of ceramics has a scatter even if the defects are the same size. Therefore in this paper we propose a model for fracture of ceramics by introducing the probability distribution of fracture toughness. Based on this model, a simple method is developed to predict the fracture probability for ceramics structures with arbitrary shapes. Four-point-bending tests of alumina ceramics are carried out to examine the validity of the present method. Good agreement between the test results and those predicted by the developed method has been obtained.