1 0 0 0 OA 超音波周波数におけるステンレス薄板の曲げ疲労試験
- 著者
- 秋庭 義明 木村 英彦 鶴 尋貴 中村 亜有子
- 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.74, no.742, pp.879-884, 2008-06-25 (Released:2011-03-02)
- 参考文献数
- 18
- 被引用文献数
- 1
Fatigue test system for thin sheets was constructed using an ultrasonic fatigue testing machine. Specimens were fixed at the location where the displacement amplitude became the maximum. The specimen was fatigued under full-reverse bending. Displacement at a fixed edge of the specimen and the deflection of the specimen were measured with a laser displacement gage during fatigue tests. Modal analysis was carried out to determine the dimensions of the specimen and to calculate the applied stress on the basis of the flexural displacement amplitude. The maximum stress was observed on the free side edge near the fixed edge. Two kinds of martensitic stainless steel sheets, SUS301-CSPH and SUS632J1-CSP, were fatigued with the fatigue test system. The thickness of the specimen was 83 and 106μm, respectively. The 3rd vibration mode was selected for fatigue tests. The fatigue cracks initiated from the free side edge of the specimen. For the case of shorter fatigue life, fatigue strength for both stainless steels were almost identical. On the other hand, for longer fatigue life, fatigue strength of SUS632J1 is higher than that of SUS301.
1 0 0 0 OA 炭化ケイ素長繊維強化チタン合金における疲労き裂の伝ぱと繊維架橋応力の測定
- 著者
- 秋庭 義明 木村 英彦 原 航平 田中 啓介
- 出版者
- 公益社団法人 日本材料学会
- 雑誌
- 材料 (ISSN:05145163)
- 巻号頁・発行日
- vol.54, no.7, pp.698-703, 2005 (Released:2006-04-07)
- 参考文献数
- 13
Single edge notched specimens of a unidirectional SiC long fiber reinforced titanium alloy were fatigued under four point bending. Propagation behavior of fatigue cracks was observed on the basis of the effect of the fiber bridging. The branched fatigue cracks were initiated from the notch root. The crack propagation rate decreased with crack extension due to the crack bridging by reinforced fibers. The longitudinal stress in the reinforced fiber was measured by using high spatial resolution synchrotron radiation. The interfacial frictional stress between the matrix and the fiber could be directly determined by X-ray method. The bridging stress was also measured as a function of a distance from a crack-tip. The stress intensity factor range corrected on the basis of the shielding effect agreed well with that for the monolithic titanium alloy, when compared at the same crack propagation rate.