岩石の疲労寿命の分布特性と破壊機構
1973 年 22 巻 233 号 p. 153-158
詳細
1973 年 22 巻 233 号 p. 153-158
In this paper, the authors discuss the failure process of rock which would result in the extremely wide fluctuation of fatigue lives observed in their fatigue tests under pulsating compressive or tensile stress.
Under the assumption that the process of fatigue failure is a stochastic process, it is indicated that the probability of survival of rock specimen is expressed as a linear combination of two exponential functions. This means that the failure process of rock is neither serial nor cumulative, but consists of two parallel Poisson processes of first order.
Other probable explanations of test results are assumed and discussed. The first of such assumptions is that each of rock specimen has a different rate constant of failure. This is discussed but denied from the theoretical point of view.
The second one is that the failure process is serial and cumulative. In order to verify whether the failure process of rock is serial or not, the fatigue test by the multiple-repeated tensile stress was carried out, using the same rock samples as in the previous fatigue tests. The test result shows that the failure process of rock is not a serial process.
Together with other test results reported in the previous papers, it is concluded that the process of fatigue failure of rock consists of two parallel Poisson processes of first order.
