熱衝撃負荷下におけるセラミックスのき裂進展のAE法による検出および破壊力学的特性評価

抄録

The mixed mode crack extension behavior of ceramics under thermal shock was dynamically evaluated by a disc-on-rod test and AE measurement. In this test, the transient temperature distribution was measured by an infrared(IR) camera. The microfracture process was dynamically characterized by acoustic emission (AE) measurement, and the crack extension path were observed by a video camera. Using elliptical specimens and elliptical rods, mixed-mode crack extension behavior was characterized. Intermittent crack extension was observed as the temperature distribution changed, and AE signals were detected at the same time. The fracture mechanical parameter of the mixed mode crack extension behavior of ceramics under thermal shock were calculated by the finite element method using the temperature distribution measured by an IR camera. It was confirmed the R-curve behavior in which crack extension resistance increases with crack extension. Consequently, the fundamental insight for the integrity assessment of ceramic structures under thermal shock was obtained.