Pages 173-174
Distribution of COD in Silicon Nitride was measured at room temperature using Digital Image Correlation Method after cyclic bending fatigue tests. The cyclic fatigue tests with moving crack and stationary crack were performed under stress ratios R=0.1,0.5 and -1 at room temperature and 1273K. From the experimental results, the stress shielding effect under cyclic loading was discussed quantitatively. The stress shielding effect after the test at 1273K was more significant than that at room temperature under any stress ratio. Though the stress shielding effect under R=-1 was stronger than that under R=0.1 at room temperature, results obtained after the test at 1273K were found to be quite different.
