- 著者
- 橋本 翔 小俣 弘樹 松永 久生
- 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 (ISSN:21879761)
- 巻号頁・発行日
- vol.83, no.852, pp.16-00585-16-00585, 2017 (Released:2017-08-25)
- 参考文献数
- 17
- 被引用文献数
- 1
Rolling contact fatigue (RCF) tests were conducted using rolling bearings with a micro-drilled hole on the raceway. In all the tests, fatigue crack initiated at the edge near the bottom of the hole, and then propagated by shear mode. Even in the unbroken specimens tested up to N = 1×108 cycles, a short fatigue crack was found at the edge. By using stress intensity factor (SIF) range calculated for initial defect size, fatigue life data were uniformly gathered inside a small band irrespective of the diameter and depth of the hole. In addition, it was found that the crack size dependency of threshold SIF range, which is well-known for mode I fatigue crack, also exists in mode II fatigue crack emanating under the rolling contact. The values of threshold SIF ranges obtained by the RCF tests were in good agreement with those obtained in the torsional fatigue tests under a static compression.
- 著者
- 橋本 翔 小俣 弘樹 松永 久生
- 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 (ISSN:21879761)
- 巻号頁・発行日
- vol.83, no.852, pp.16-00584-16-00584, 2017 (Released:2017-08-25)
- 参考文献数
- 19
It has been shown that rolling contact fatigue (RCF) test using specimen having a small drilled hole is a useful method for evaluating the effect of small defect on flaking strength of steels. In this study, RCF tests of rolling bearings having a small drilled hole were carried out. The flaking failure was considered as a problem of shear-mode fatigue crack emanating from the small defect. As a first step to quantify the crack-growth threshold on the basis of fracture mechanics, mode II stress intensity factor range, ΔKII, of a ring-shaped crack emanated around the edge of a drilled hole under the passing of a rolling element was analyzed by using finite element method. And then, the obtained values were correlated with the ΔKII values of penny-shaped cracks in an infinite body under uniform shear through the intermediary of a correlation factor, fdrill. The stress intensity factor of the ring-shaped crack was uniformly correlated with that of the penny-shaped crack by the single factor fdrill irrespective of hole diameter, d, depth of hole edge, h’, and maximum contact pressure, qmax, within the ranges: d = 0.05 ~ 0.2 mm, h’ = 0.05 ~ 0.345 mm and qmax = 2.0 ~ 3.0 GPa. The obtained results will be applied for the quantification of RCF test results shown in the subsequent paper.