著者

金子 淳一 細矢 直基 古屋 耕平

出版者

一般社団法人 日本機械学会

雑誌

Dynamics & Design Conference 2010 (ISSN:24242993)

巻号頁・発行日

pp._111-1_-_111-6_, 2010-09-14 (Released:2017-06-19)

被引用文献数

2 3

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This paper discuses the way to reduce the noise and vibration of thin plate structures. This paper focuses on the musical saw, a kind of musical instrument. The musical saw is thin plate and it is need to bend the saw as S-curve, to play the instrument. Thin plate structures used for various products. In some case, curvature is laid on thin plate structures to enhance the rigidity. If musical saw and thin plate structures conditions are matched, it will be noise problem. Investigating that the relationship between the sound pressure, S-curve, boundary condition, and aspect ratio of the saw by experiment and FEA, it is discussed to apply the investigation result to the thin plate structures.

著者

宮本 大資 梶原 逸朗 細矢 直基 西留 千晶

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C編 (ISSN:18848354)

巻号頁・発行日

vol.77, no.777, pp.1760-1771, 2011 (Released:2011-05-25)

参考文献数

11

被引用文献数

2 2

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This paper proposes a vibration testing and health monitoring system based on an impulse response excited by a laser ablation. High power YAG pulse laser is used in this system for producing an ideal impulse force on structural surface. It is possible to measure high frequency vibration responses in this system. A health monitoring system is constructed by this vibration testing system and a damage detecting algorithm. A microscopic damage of structures can be extracted by detecting fluctuations of high frequency vibration response with the present health monitoring system. In this study, loosening of bolt tightening torques is defined as the damage of the system. The damage is detected and identified by statistical evaluations of measured frequency response data with Recognition-Taguchi method.

著者

細矢 直基

出版者

渋沢栄一記念財団

雑誌

青淵 (ISSN:09123210)

巻号頁・発行日

no.874, pp.22-24, 2022-01

著者

秋田 涼佑 梶原 逸朗 細矢 直基

出版者

一般社団法人 日本機械学会

雑誌

Dynamics & Design Conference 2016 (ISSN:24242993)

巻号頁・発行日

pp.343, 2016 (Released:2017-06-19)

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This paper proposes a health monitoring system for detecting a hole opened on a pipe based on laser plasma acoustic excitation and acoustic measurement. In this system, the acoustic excitation is applied to the pipe by the laser-induced plasma in the air, which is generated by a high-power Nd: YAG pulse laser. Non-contact acoustic impulse excitation can be realized by laser-induced plasma. A microphone is used for measuring the time response of acoustic pressure. In this study, the detection of the hole on the pipe is focused. The time response of acoustic pressure changes due to reflection of acoustic wave caused at the hole opened on the pipe. The position of the hole is identified by applying continuous wavelet transform to time response of with/without the hole.

著者

細矢 直基 前田 真吾

出版者

芝浦工業大学

雑誌

挑戦的研究(萌芽)

巻号頁・発行日

2017-06-30

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生体組織の病変を早期に発見するために,生体組織を外部から加振し,その際の応答を核磁気共鳴画像法 (Magnetic Resonance Imaging: MRI) により,生体組織に伝播する波動を可視化し,その弾性率を評価する方法として,Magnetic Resonance Elastgraphy (MRE) が検討されている.しかし,広範囲な弾性値を持つ様々な生体組織に対応するためには,十数Hz~数十kHzまでの広帯域な周波数成分を含む入力が必要であるが,加振器のような接触式デバイスでは非常に軟らかい生体組織に対して広帯域な周波数成分を含む入力を作用させることができない.本研究では,所望の音響放射パターン(指向性)に単一デバイスで制御できる,直径数mmの大きさの誘電エラストマーアクチュエータ (Dielectric Elastomer Actuator: DEA) を用いた音源デバイスを創成する.平成29年度は,風船型球面DEAを実現した.柔軟電極をカーボンブラック,誘電エラストマーをアクリル系とし,空気圧により膨らませることで球面DEAとした.この風船型球面DEAスピーカの形状を計測したところ,真上から見た形状は直径15 mmの円,真横から見た形状は長径15 mm,短径12 mmの楕円であった.膨張前の薄膜DEA(円板)の面積が78.5 mm^2,風船型球面DEA(楕円殻)の表面積が2459.2 mm^2であるので,3033 %拡大することに成功した.また,この風船型球面DEAの音響放射特性,振動特性を計測することで,音源デバイスとして有効であることを検証した.さらに,音響放射特性と風船型球面DEAスピーカの振動モード形との関係を調べた.

著者

渡邉 鉄也 伊藤 淳二 田中 基八郎 細矢 直基

出版者

日本感性工学会

雑誌

感性工学研究論文集 (ISSN:13461958)

巻号頁・発行日

vol.2, no.2, pp.43-48, 2002-08-31 (Released:2010-06-28)

参考文献数

6

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A human being laughs in every day life when happy, and a facial expression changes unconsciously. It is thought that the facial expression has close relation to feelings and Kansei. The facial expression is more intelligibly than the expression by word, and can convey a delicate nuance when introducing feelings. Intention communication with a different foreigner is possible by a facial expression and a gesture. In this way, the role that a facial expression serves as by communication is very big. The aim of this study is to control a mind state by the intentionally modified facial expression. The final aim is the application to a field of the medical welfare. In this study, measuring the behavior of each muscle of a face using electromyogram in order to evaluate the expression quantitatively elucidates the mechanism of a facial expression. Six facial expressions is paid attention. When a human being made a facial expression intentionally, it is thought that a mind state changes by the facial expression. For example, it is said that a mind state is stable unconsciously when making a smile intentionally. On the other hand, it is thought that a mind state becomes unstable when a partner makes a facial expression of anger. In this way it is thought that a mind state is closely related to a facial expression, but there are many subjects that have not been elucidated. So the relation of a facial expression and a mind state is cleared from bio-information such as electromyogram or brain waves as an engineering approach and will be applied to the medical welfare.

著者

宮本 大資 梶原 逸朗 細矢 直基

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C編 (ISSN:18848354)

巻号頁・発行日

vol.77, no.784, pp.4402-4412, 2011 (Released:2011-12-25)

参考文献数

8

被引用文献数

1 1

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This paper proposes a contactless vibration testing system for rotating disks based on an impulse response excited by a laser ablation. High power YAG pulse laser is used in this system for producing an ideal impulse force on structural surface without contact. The contactless vibration testing system is composed of a YAG laser, laser Doppler vibrometer and spectrum analyzer. This system makes it possible to measure vibration characteristics of structures under operation, such as vibration measurement of a rotating disk. The effectiveness of this system is confirmed by experimental and theoretical analyses. In this paper, a platter of hard disk drive is employed as an experimental object. Vibration characteristics of a rotating and non-rotating platter are measured and compared with the results of theoretical analysis.