著者

後藤 真宏 西谷 弘信 宮川 浩臣 柳川 恭広

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 A編 (ISSN:03875008)

巻号頁・発行日

vol.54, no.499, pp.497-502, 1988-03-25 (Released:2008-02-21)

参考文献数

13

被引用文献数

2 2

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Using a series of base oils of different viscosity grades, rotating bending fatigue tests of 0.34 % C steel plain specimens were carried out to examine the effect of oil environments on the fatigue behavior. Although the effect of oil is hardly observed in one grain size crack initiation process, its effect appears in the crack propagation process. As the main effects of oil, two actions are considered ; that is, the isolation of the atmosphere and the oil wedging action. The propagation of a crack smaller than 0.1mm is controlled mainly by the former effect. For a crack larger than 0.1mm, its behavior is controlled mainly by the latter effect. On the other hand, the effect of oil on the fatigue limit is very small.

著者

皮籠石 紀雄 西谷 弘信 後藤 真宏 豊廣 利信 北山 智

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.59, no.557, pp.57-61, 1993-01-25

被引用文献数

2 2

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Statistical analysis is necessary in evaluating the fatigue life of structures. In the present study, rotating bending fatigue tests were carried out on specimens with two small blind holes of a 5052 A1 alloy in order to investigate the distribution characteristics of the fatigue crack growth life based on the small-crack growth law dl/dN= C_1σ^n_al. The crack growth rate in each specimen was determined uniquely by σ^n_al, therefore the crack growth life can be predicted by the small-crack growth law. On the assumption that the value of n is a fixed one and the value of C_1 is a random variable, the distribution of the crack growth rate can be evaluated through the value of C_3 in the relationship dl/dN=C_3l. C_3 follows a Weibull distribution approximately. The calculated distribution of the ocracy growth life based on the small-crack growth law and the distribution of C_3 was in good agreement with the experimental results.