半だ円表面き裂を有するJISファインセラミックス曲げ試験片の三点曲げおよび四点曲げの解析

抄録

Ceramics are brittle materials. Therefore, it is important to evaluate the fracture toughness of them. Mendiratta et al. proposed the Indentation-Induced Flaw method to evaluate the fracture toughness of ceramic materials. This method is simple and useful. However, the values of stress intensity factor for a semi-elliptical surface crack in the specimens under three-or four-point bending are necessary to obtain the fracture toughness. We calculate the accurate stress intensity factors for JIS ceramic bending specimens with a semi-elliptical surface crack under three-or four-point bending. The approximate expressions for the stress intensity factors are also given.