脱塵フィルター用多孔質炭化ケイ素の繰返し疲労寿命

抄録

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, σ_max, and the fatigue life, N, was expressed as σ_maxⁿN=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.