著者

岡島 智史 岩崎 篤 泉 聡志 酒井 信介

出版者

一般社団法人 日本高圧力技術協会

雑誌

圧力技術 (ISSN:03870154)

巻号頁・発行日

vol.43, no.6, pp.335-340, 2005 (Released:2005-12-26)

参考文献数

6

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The verification test of machine diagnosis techniques was carried out by Japan Power Engineering and inspection Corporation, and a system called as the RET (Residual Life Evaluation of Thermal Power Plants) system was developed as the result of this activity. The RET system can evaluate the primary damage of equipments in boiler or turbine using several residual life evaluation methods. The RET system provides valuable function for the residual life evaluation. However, this system is not necessarily utilized widely. In this study, online version of the RET system is developed for the purpose of populization of the RET system. The online RET system can evaluate the primary damage of the equipments in boiler or turbine without any extra application, and is easy to reflect new information.

著者

泉 聡志 横山 喬 寺岡 卓也 岩崎 篤 酒井 信介 斎藤 金次郎 名川 政人 野田 秀樹

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.71, no.703, pp.380-386, 2005-03-25

被引用文献数

8 16

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We have developed a new nut named 'super slit nut (SSN)', which realizes anti-loosening performance without complicated tightening procedures. In this study, tightening behavior and loosening behavior caused by shear load are analyzed by mean of three-dimensional finite element method. It is found that SSN has a prevailing torque of 15 to 19Nm, which closely agrees with experimental data. The load distribution of thread depends on the rotation angle of nut. At the angle of 24.6 degree, the distribution of 1st pitch turns to be 10% larger than that of conventional nut, reflecting the decrease in the thread at slit region. It is also found that the anti-loosening performance cas be realized by the thread contact force at the slit region. Since its contact force does not depend on the tightening force, the effect of anti-loosening performance drastically increases as the tightening force is decreased. Shear fracture would initiate not at slit region but at the bottom of 1st thread, whose stress is about 10% larger, as compared with conventional nut. Moreover, by mean of tensile and fatigue experiments, it is concluded that SSN involves sufficient strength in practical use.

著者

岩崎 篤 桑原 秀剛 轟 章 杉谷 恒也

出版者

一般社団法人日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2004, no.10, pp.207-208, 2004-03-03

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This research is about a statistical diagnostic method for a structural health monitoring which is applicable to existing structures from the present moment. In this method, structural condition is statistically diagnosed by change of a response surface which is regression model of sensor's outputs. Change of response surface is statistically tested with F-test. In the F-test, a threshold value of normal/troubled condition is simply decided from a theoretical F-probability distribution. Therefore, this diagnostic method only requires data of intact condition and does not require the complicated modeling and information of troubled condition. To confirm the effectiveness of the presented method, health monitoring of jet fan is conducted. Load cells are mounted to a supporting system of the jet fan. Response surface is calculated from vibration data measured by the load cells. As a result, structural condition of the jet fan is successfully diagnosed with the method.