抄録
In order to investigate the length of cracks developed by stress corrosion and cyclic fatigue and the time to failure under cyclic loading in compression, the equations proposed by Costin et al. is estimated from the results of creep and fatigue tests for OGINO tuff, KIMACHI sandstone and AKIYOSHI marble. Under the fatigue tests at cyclic frequency of 1 Hz, the ratio of the length of crack due to stress corrosion to the total one increases with increasing upper stress ratio. The length of crack due to cyclic fatigue is proportional to the exponent of cyclic frequency of stress, and the time to failure is affected by it. Also, in case that the length of crack due to stress corrosion occupies the most part of the total crack length, the increase in the time to failure is smaller with decreasing frequency. The time up to failure is longer as the stress amplitude decreases, but below a given ratio of stress amplitude, it is smaller with decreasing the ratio of stress amplitude. Also, the ratio of stress amplitude, at which the time to failure takes a maximum value, and the length of crack due to cyclic fatigue are smaller as the ration of stress amplitude decreases.
