2000 年 49 巻 3 号 p. 304-309
A new low-capacity fatigue testing machine was developed to evaluate the cyclic fatigue behavior of porous ceramics used for dust filters. Cyclic fatigue tests were conducted by cyclic four-point bending with the stress ratio 0.5 at a room temperature. The results were summarized as follows:
(1) The distribution of cyclic fatigue life at a given stress level can be expressed as a two-parameters Weibull distribution. From the Weibull distribution of the life, the exponent of the crack propagation equation as a function of the stress intensity factor was estimated to be 25.3.
(2) The fatigue life decreased with increasing maximum stress. The relation between the maximum stress, σmax, and the fatigue life, N, was expressed as σmaxnN=const. The exponent of the crack propagation equation determined from the S-N relation was 20.3 which was close to the value determined of the life distribution.
(3) Cyclic loading induced a residual bending deformation in the specimen. The amount of residual deformation increased with increasing number of stress cycles.