セラミックスの強度信頼性評価(第4報)

複数亀裂群を有するセラミックスの亀裂進展特性の解析

抄録

In this paper, the fatigue crack growth characteristics of PSZ ceramics with multiple cracks is described concerning with the number of cracks, crack spacing and crack length. The stress distribution around the crack tips has been analyzed in the case of four point bending test model using the finite element method. It is confirmed that the maximum principal stress value of crack tips decreases with increasing the number of crack and narrowing the crack spacing. Also, the maximum principal stress value of crack tips which lead to fracture is changed by growth of other cracks, which are independent from failure. On the other hand, crack growth rate parameter m, -logC in multiple cracks are calculated from stress intensity factor K, which is analyzed by J-integral around the crack tip. It is found that the estimated life of PSZ ceramics with multiple cracks agrees with the fatigue life which is elucidated from fatigue test.