田中 昂 (タナカ タカシ)

TANAKA Takashi

写真a

職名

講師

研究分野・キーワード

機械力学,振動工学,構造ヘルスモニタリング

プロフィール

 近年、機械の劣化に起因する製造品の不良やインフラ構造物の老朽化事故が問題視されています。これまでに、壊れてから対応する事後保全から定期的に点検をするタイムベースの予防保全への移行がなされています。現在では、タイムベースの保全だけでは十分に対応できない問題に対応するために、センサを取り付け、常時状態を監視するコンディションベースの予防保全,さらには状態監視から危険度合いを診断し対応するリスクベースの予知保全への移行が求められています。予知保全を実現するためには、故障や損傷などの不具合の検出(程度評価、位置同定)、健全性診断、余寿命推定、診断および推定結果に基づくメンテナンス計画の作成など、多岐にわたる技術が重要となります。予知保全の実用化に向けて、保全サイクルのスタートである不具合の検出(程度評価、位置同定)、健全性診断技術の開発を行っています。その中でも、振動計測に基づく検査技術全般や機械、構造物のIoT化,知能化に興味を持っています。現研究課題は、微小な不具合に敏感な超音波振動を用いた接触型損傷検出技術開発に取り組んでいます。今後、デジタルツインのためのダイナミクスの物理モデリング手法や機械・構造物のIoT化、知能化におけるダイナミクスの果たす役割の高度化、導入の容易化にも取り組んでいきます。

出身大学院 【 表示 / 非表示

  • 京都工芸繊維大学  工芸科学研究科  設計工学専攻  博士課程  2015年03月

取得学位 【 表示 / 非表示

  • 博士(工学)  京都工芸繊維大学  2015年03月

  • 修士(工学)  京都工芸繊維大学  2012年03月

学内職務経歴 【 表示 / 非表示

  • 滋賀県立大学  工学部  機械システム工学科  講師   2019年04月 ~ 現在

  • 滋賀県立大学  工学部  機械システム工学科  助教   2015年04月 ~ 2019年03月

所属学会・委員会 【 表示 / 非表示

  • 日本機械学会  

  • 非破壊検査協会  

  • 設備管理学会  

研究分野(科研費分類) 【 表示 / 非表示

  • 機械力学・制御

 

論文 【 表示 / 非表示

  • Evaluation of contact-type failure development based on frequency modulation due to nonlinear wave modulation utilising self-excited ultrasonic natural vibration

    Takashi Tanaka, Yasunori Oura, Syuya Maeda

    COMADEM International  International Journal of Condition Monitoring and Diagnostic Engineering Management  25 (2)   59 ~ 66  2022年06月

    共著  共同(主担当)

    [概要]

    This paper presents a novel evaluation method of contact-type failure development based on nonlinear wave modulation utilising self-excited ultrasonic vibration. The contact-type failure, e.g. fatigue crack, delamination of composite material and debonding, is difficult to detect by using linear ultrasonic waves or vibrations. When the contact condition of the contact-type failure is fluctuated caused by structural low-frequency vibration, the amplitude and phase of ultrasonic waves passing nearby the failure area is fluctuated in synchronization with low-frequency vibration (nonlinear wave modulation). The fluctuation of natural frequencies caused by fluctuation of local contact stiffness is the cause of this amplitude and phase fluctuation. Therefore, frequency of ultrasonic natural vibration excited by local feedback control changes, chasing the change of natural frequency automatically. Thus, the frequency fluctuation of ultrasonic natural vibration in synchronization with low-frequency vibration (frequency modulation) occurs caused by nonlinear wave modulation. In this paper, the experimental investigation of proposed evaluation method is performed. Especially, the dependence of the proposed evaluation index of contact type failure on the viscous damping is clarified. Firstly, the design of an analogue circuit of local feedback control is explained. Secondly, it is confirmed that the self-excitation of ultrasonic natural vibrations can be implemented. Finally, it is clarified that the variation width of the frequency fluctuation is a novel evaluation index of contact-type failure level, which is independent from the variation of the viscous damping.

  • Evaluation of Contact-Type Failure Using Frequency Fluctuation Caused by Nonlinear Wave Modulation Utilizing Self-excited Ultrasonic Vibration

    Tanaka T., Oura Y., Maeda S., Wu Z.

    Lecture Notes in Mechanical Engineering  Lecture Notes in Mechanical Engineering   163 ~ 175  2022年01月

    10.1007/978-3-030-93639-6_14  共著  共同(主担当)

    [概要]

    This study concerns the evaluation method of contact-type failure, which is difficult to detect by linear ultrasonic because of transmission of ultrasonic at the contact surfaces utilizing frequency fluctuation caused by nonlinear wave modulation. When the contact-failure is vibrated by low-frequency vibration, the amplitude and phase of ultrasonic in the vicinity of the failure area is fluctuated in synchronization with low-frequency vibration (nonlinear wave modulation). This amplitude of amplitude fluctuation and phase fluctuation is the evaluation index of contact-type failure. However, the change in this index depends on the viscous damping of the structure. In the nonlinear wave modulation utilizing self-excited ultrasonic vibration, the frequency of ultrasonic vibration is fluctuated by low-frequency vibration. The frequency fluctuation may be the evaluation index of contact-type failure independent of the viscous damping of the structure. In this paper, the experimental verification using beam structure is done. Firstly, the self-excitation technique of ultrasonic natural vibration using feedback control is introduced. Secondarily, it is shown that the amplitude of frequency fluctuation is the evaluation index of contact-type failure by experiment. The uniform beam structure with simulated failure, which is simulated the contact-type failure is used. The vibration characteristics of this structure and the self-excited ultrasonic vibration excited by feedback control can measure easily. Finally, the viscous damping dependency of the frequency fluctuation is investigated. As the result, it is shown that the amplitude of frequency fluctuation is the evaluation index independent of viscous damping.

  • Localization method of contact-type failure by measuring the structural intensity of low-frequency vibrations caused by frequency down-conversion of elastic vibrations

    Takashi Tanaka, Junnosuke Asano, Yasunori Oura

    日本機械学会  Mechanical Engineering Journal  8 (5)   21-00201 ~  2021年10月

    10.1299/mej.21-00201  共著  共同(主担当)

    [概要]

    Contact-type failures, such as early-stage fatigue cracks, bolt loosening, and welding cracks, are difficult to detect with nondestructive inspection, which uses ultrasonic waves or vibrations. When a structure experiencing contact-type failure vibrates due to ultrasonic vibrations of two different frequencies, low-frequency vibrations with frequencies equal to the difference between the frequencies of the ultrasonic vibrations are generated due to local nonlinearity at the contact interface (frequency down-conversion). The detection methods of contact-type failure based on the frequency down-conversion of elastic waves or vibrations have been proposed. These detection methods can be applied using measurements with low-sampling rates. This study aims to develop a detection and localization method based on the frequency down-conversion of elastic vibrations. Low-frequency vibrations caused by frequency down-conversion are generated only if the structure has contact-type failure. Accordingly, contact-type failure can be regarded as the excitation point of low-frequency vibration caused by frequency down-conversion. Herein, a localization method of contact-type failure using the structural intensity as the localization method of the exciting location was proposed. First, an overview of the frequency down-conversion phenomenon is mentioned. Second, the theoretical investigation of the proposed localization method is explained, and the parametric excitation model that uses the Euler-Bernoulli beam is suggested. The equation transformation of the proposed model clarifies that the contact-type failure can be regarded as the exciting point of low-frequency vibration. Furthermore, from the results obtained herein, the location of contact-type failure was identified as the exciting point of low-frequency vibration caused by the frequency down-conversion. Finally, the basic performance of the proposed localization method was experimentally investigated. The exciting point can be localized from the sign change point of the structural intensity. Thus, the sign change point of the structural intensity of low-frequency vibrations caused by the frequency down-conversion is the contact-type failure location.

  • Excitation of ultrasonic natural vibrations by multi-excitation using decentralized control for failure monitoring

    Tanaka T., Tamura T., Oura Y.

    Proceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021  Proceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021    2021年09月

    10.1115/SMASIS2021-67457  共著  共同(主担当)

    [概要]

    The failure, e.g. fatigue crack, weld crack, and bolt loosening, of infra-structure is one of the causes of serious accidents. To prevent these accidents, structural health monitoring systems have been proposed. Among them, the evaluation methods by measurement of natural vibrations are useful for various structures because of ease in introducing a monitoring system. Currently, the natural vibrations at lowfrequency range are usually used because of the difficulty of exciting natural vibrations at high-frequency range. In this paper, the excitation method of natural vibrations by multi excitation using decentralized control is developed. Firstly, the difficulty of excitation of ultrasonic natural vibrations is confirmed. Secondly, the basic performance of the multiexcitation using decentralized control is investigated by the experiment using a simple beam structure. The excitation of an ultrasonic natural vibration in the case of multi-excitation using decentralized control with the self-excitation automatically is examined. From the phase differences between each measurement signal, it is clarified that mutual synchronization is realized. Thus, it is confirmed by the measurement of vibration mode shape that an ultrasonic natural vibration is excited. Finally, it is tried to excite another natural vibration by forced entrainment.

  • Localization of multiple contact-type failures using structural intensity of low-frequency vibration caused by frequency downconversion

    Tanaka T., Asano J., Oura Y.

    Proceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021  Proceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021    2021年09月

    10.1115/SMASIS2021-67739  共著  共同(主担当)

    [概要]

    The contact-type failure, e.g. fatigue crack in early stage, delamination of composite material and adhesive failure, leads to the serious accidents. When the object with the contact-type failure vibrates due to ultrasonic vibrations of different frequencies, the interaction of the contact interfaces of failure occurs. As the result of this interaction, the low-frequency vibration, of which frequency is the difference frequency of ultrasonic vibrations, generates (Frequency down-conversion). The detection, evaluation and localization by measurement of structural intensity of low-frequency vibration caused by frequency down-conversion has been proposed. In this paper, the performance of the proposed method in the case of multiple contact-type failures is investigated. Firstly, the detection method of contact-type failure based on frequency downconversion of elastic vibrations is introduced. Overview of frequency down-conversion and the example of detection of contact-type failure is shown. Secondly, the proposed method for single failure is explained. By the measurement result of structural intensity of the low-frequency vibration caused by frequency down-conversion, it is confirmed that the contact-type failure can localize as the excitation point of low-frequency vibration. Finally, the influence of other failures on the localization accuracy is investigated. From these results, it is clarified that the contact-type failure, of which the excitation force of low-frequency vibration is the largest, only localizes.

  • Detection of contact-type failure based on nonlinear wave modulation utilising ultrasonic vibration driven by self-excitation

    Takashi Tanaka, Yasunori Oura, Syuya Maeda

    COMADEM International  International Journal of Condition Monitoring and Diagnostic Engineering Management  24 (2)   43 ~ 49  2021年04月

    共著  共同(主担当)

    [概要]

    In this paper, a novel method is proposed for detecting contact-type failure based on nonlinear wave modulation utilising ultrasonic vibration driven by selfexcitation. In particular, the purpose of this paper is to propose an evaluation index independent of the viscous damping of the contact-type failures. When the structural element of an infrastructure with contact-type failures vibrates at low frequency caused by environmental disturbance or forced excitation, the contact stiffness of failure fluctuates in synchronisation with low frequency. In this case, the transfer characteristic of ultrasonic vibration fluctuates due to the fluctuation of contact stiffness. As a result, the amplitude and phase of ultrasonic vibration were modulated in synchronisation with low frequency (nonlinear wave modulation). The essence of nonlinear wave modulation is the fluctuation of natural frequency caused by the fluctuation of modal stiffness. Therefore, this phenomenon can be expressed as a time-varying system caused by the fluctuation of natural frequency. In this research, the concept of a novel method for detecting contact-type failures utilising ultrasonic vibration driven by self-excitation was investigated using time response analysis. The self-excitation method by feedback control (local feedback control) using collocated sensor and actuator is the excitation method of natural vibration automatically. Therefore, the frequency of the ultrasonic vibration excited by local feedback control fluctuated simultaneous with the fluctuation of natural frequency caused by nonlinear wave modulation. It is clarified that the fluctuation range of frequency of ultrasonic vibration corresponds to the evaluation index of development of the contact-type failure independent of viscous damping.

  • Finite element investigation of using cartilage plate with varying thickness in cartilage myringoplasty

    Zhiqiang Wu, Kazuki Kamitani, Takashi Tanaka, Yasunori Oura

     Proceedings of the 15th International Conference on Motion and Vibration Control (MoViC2020)  (10094)    2020年12月

    共著  共同(副担当)

    [概要]

    This research aims to find a better design of cartilage plate used in myringoplasty, a surgical procedure to reconstruct the tympanic membrane (TM) of human middle ear when it is perforated. A detailed three-dimensional finite element model of human middle ear is created and used to investigate the effects of thickness variation of cartilage plate on sound transmission. The validity of the numerical model is verified by comparing the vibration response of the stapes footplate with that of the measurement results of other researchers under a sound pressure of 90 dB. Then, a reconstructed model is created by replacing an assumed perforation on the TM with a uniform thickness cartilage plate. Varying the thickness of cartilage plate from 0.1 mm to 0.7 mm, and evaluating the displacement of stapes footplate in a frequency range from 0.1 kHz to 10 kHz, frequency response analysis show that 0.3-0.5 mm models have the best performance than others. However, from the viewpoint of quality of life (QOL), there is still a large difference between the performance of reconstructed models and that of the heathy model. As a further investigation, instead of adopting a uniform thickness, the thickness of the cartilage plate is designed into several patterns by combination of thinner layers and thicker layers. The frequency response curves of some patterned models show better matching to the curve of healthy model than using uniform thickness plate. From these results, a further improvement can be expected by optimizing the pattern design.

  • Detection of Contact-type Failure by Measurement of Structural Intensity of Low-frequency Vibration Caused by Frequency Down-conversion of Elastic Vibrations

    Takashi Tanaka, Junnosuke Asano, Yasunori Oura, Zhiqiang Wu

     Proceedings of the 15th International Conference on Motion and Vibration Control (MoViC2020)  (10036)    2020年12月

    共著  共同(主担当)

    [概要]

    This study concerns the detection method of contact-type failure based on frequency down-conversion of elastic vibrations. Frequency down-conversion is the phenomenon caused by contact acoustic nonlinearity (CAN) caused by large amplitude ultrasonic vibrations. The contact condition is fluctuated by large amplitude ultrasonic vibration. In this condition, the scatter characteristic of another ultrasonic vibration, of which frequency is close to the large amplitude ultrasonic vibration, fluctuates. As this result, the low-frequency vibration, of which frequency is the difference frequency between two ultrasonic vibrations, generates. The detection method of the contact-type failure based on frequency down-conversion of elastic vibrations is useful to detect small failure. In this study, the novel detection and localization method by measurement of structural intensity of low-frequency vibration is proposed. Frequency down-conversion generates, only when the object has a contact-type failure. Therefore, the contact-type failure can be regarded as an exciting source of low-frequency vibration. The localization of contact-type failure realizes by the measurement of structural intensity of low-frequency vibration caused by frequency down-conversion as a detection method of exciting point. In this paper, the basic investigation of the proposed method is done by experiment using simple cantilever. Firstly, the vibration mode of low-frequency vibration caused by frequency down-conversion is measured. It is shown that the estimation of a failure location from vibration mode shape is difficult. Secondly, the concept of the proposed method is introduced. The structural intensity of the low-frequency vibration is calculated using the measured vibration mode. It is shown that the detection and localization of the contact-type failure can be realized by the measurement of the structural intensity. Finally, the basic investigation of the proposed method is done by experiment. It is confirmed that the sign of the structural intensity of low-frequency vibration caused by frequency down-conversion changed at the failure location.

  • 非線形波動変調によって生じる固有振動数変動を用いた接触型損傷の程度評価(時刻歴応答解析による固有振動数変動推定手法の検討)

    田中 昂,大浦 靖典,前田 秀哉,呉 志強

     日本機械学会論文集  86 (889)   20-00105 ~  2020年09月

    10.1299/transjsme.20-00105  共著  共同(主担当)

    [概要]

    This research presents the evaluation method of contact-type failure level based on nonlinear wave modulation. It is difficult to detect contact-type failures using a linear ultrasonic inspection. The detection method based on nonlinear wave modulation has been proposed to detect the contact-type failure. Nonlinear wave modulation is the phenomenon, which is explained by contact acoustic nonlinearity (CAN) of ultrasonic caused by low-frequency vibration. The SDOF model for nonlinear wave modulation consists of modal mass, modal damping and modal stiffness which coefficient fluctuates caused by CAN of ultrasonic vibration. This model is described by time-varying linear model when the frequency ratio of the frequency of low-frequency vibration to frequency of ultrasonic vibration is sufficiently small. When the fluctuation frequency of coefficient of modal stiffness caused by low-frequency vibration is sufficiently smaller than the frequency of ultrasonic vibration, the instantaneous natural frequency of ultrasonic vibration fluctuates in synchronization with fluctuation of time-varying coefficient of modal stiffness. Therefore, the fluctuation of natural frequency can be used as a novel index for evaluation of failure level independent of viscous damping. In this paper, the estimation method of fluctuation of the natural frequency is proposed and verified using time response analysis. Firstly, the linear time-varying model of nonlinear wave modulation is introduced. The mechanism of fluctuation of natural frequency is explained by introduced model. Secondly, the estimation method of fluctuation of natural frequency based on the linear time-varying model is proposed. The phase fluctuation occurs as the result of the fluctuation of natural frequency. Finally, it is confirmed that the fluctuation of natural frequency can be estimated from time-invariant transfer function and phase modulation. The fluctuation range of natural frequency is the failure index.

  • Analysis of Tympanic Membrane Reconstruction with Various Thickness Cartilage Plates

    Wu Z., Tanaka T., Kamitani K., Oura Y., Hidayat H.

    IOP Conference Series: Materials Science and Engineering  IOP Conference Series: Materials Science and Engineering  886 (1)    2020年07月

    10.1088/1757-899X/886/1/012045  共著  共同(副担当)

    [概要]

    © Published under licence by IOP Publishing Ltd. The purpose of this research is to investigate an appropriate design of the sliced cartilage used for the reconstruction of the tympanic membrane (TM). A great number of people are suffering from TM perforation caused by diseases or accidents. A surgical procedure, called cartilage myringoplasty, can save the people from hearing loss by replacing the damaged part of the membrane with thin-sliced cartilage. In this research, as the first step of designing the sliced cartilage, we established a three-dimensional finite element model of the human ear for numerical analysis. The ear model consists of the middle ear (TM, ossicular chain, ligaments, muscle), and inner ear cochlea. The joints between ear bones were also modelled with softer tissues. The analysis result of the frequency response shows a good correspondence with measurement results reported by other researchers. Then, using the numerical model, we investigated the optimal thickness of the cartilage plate. The TM was cut at the bottom position with a size of about 40% of TM and filled by cartilage plate with the thickness of 0.1mm to 0.7mm. Comparing with the frequency response of the healthy ear, we found that the optimal thickness of the plate is different in a various frequency range. The reason is considered as the difference of material properties between the membrane and the cartilage. Finally, to evaluate the performance of repaired models in all frequency range, we proposed an equation of matching rate as the evaluation equation. The results show that 0.5mm cartilage plate model shows a better performance at peak response area (600Hz-1kHz), and 0.3mm. cartilage plate model shows better average performance in the total frequency range.

全件表示 >>

会議での講演 【 表示 / 非表示

  • 分散制御による多自由度振動系の固有振動励起(van der Pol型自励振動子化制御の検討)

    日本機械学会関西支部第97期定時総会講演会  2022年03月

  • 非線形圧電インピーダンス変調法による接触型損傷の検出(構造物の固有振動数変動に起因するアドミタンス変動)

    日本機械学会第19回評価・診断に関するシンポジウム  2021年12月

  • 弾性振動の周波数down-conversionに基づく接触型損傷の検出(過渡応答の時間反転解析を用いた損傷位置同定)

    日本機械学会 Dynamics & Design Conference 2021  2021年09月

  • 非線形波動変調に基づく接触型損傷の検出(伝達関数の時間変動計測による損傷評価)

    日本機械学会 Dynamics & Design Conference 2021  2021年09月

  • 自励発振と同期現象により励起した超音波帯域の固有振動計測による損傷評価に関する基礎研究

    非破壊検査協会 第28回超音波による非破壊評価シンポジウム  2021年01月

  • ディスクブレーキの面内鳴き現象(ディスク固有振動の面内外比に着目した鳴き対策)

    日本機械学会 Dynamics & Design Conference 2020  2020年09月

  • 加振点間で形成される局所的定在波を用いた非線形波動変調に基づく接触型損傷検出

    日本機械学会 Dynamics & Design Conference 2020  2020年09月

  • 振動インテンシティ計測による弾性振動の周波数down-conversionに基づく接触型損傷の位置同定

    日本機械学会 Dynamics & Design Conference 2020  2020年09月

  • 分散制御による直列結合型振動推進機構の高効率駆動(加振力の最適化による効率の向上)

    日本機械学会 Dynamics & Design Conference 2020  2020年09月

  • 分散制御による多点加振を用いた音響空間の固有振動計測(遮蔽物が音響空間の伝達特性に及ぼす影響)

    日本機械学会 Dynamics & Design Conference 2020  2020年09月

全件表示 >>

知的財産権 【 表示 / 非表示

  • 接触型異常検査装置、コンピュータプログラムおよび接触型異常検査方法

     特願2021-019168  特開2022-122088

  • 遠心送風機

     特願2016-176920  特開2018-40339

  • 制振装置

     特願2016-78865  特開2017-190794

受賞学術賞 【 表示 / 非表示

  • 日本機械学会奨励賞(研究)

     非線形波動変調に基づく接触型損傷検出の研究  国内学会・会議・シンポジウム等の賞  日本機械学会  単独  2022年04月

  • IAI 2021 Selected paper

       国際学会・会議・シンポジウム等の賞  Condition Monitoring and Diagnostic Engineering Management (COMADEM) International  共同(主担当)  2021年12月

  • 日本機械学会関西支部賞(奨励賞)

     分散制御を用いた多点加振による音響空間の固有振動計測  国内学会・会議・シンポジウム等の賞  日本機械学会関西支部  単独  2021年03月

  • COMADEM 2019 selected paper

       国際学会・会議・シンポジウム等の賞  Condition Monitoring and Diagnostic Engineering Management (COMADEM) International  共同(主担当)  2020年03月

  • TSME-ICOME 2019 Best Paper Runner-Up Award

     Analysis for Reconstruction of Tympanic Membrane with Various Thickness Cartilage Plate  国際学会・会議・シンポジウム等の賞  TSME-ICOME 2019  共同(副担当)  2019年12月

全件表示 >>

研究シーズ 【 表示 / 非表示

  • 振動問題の解決と振動を用した機械の駆動や診断

 

競争的資金(科学研究費補助金・振興調整費・JSPS等) 【 表示 / 非表示

  • 分散制御型多点加振を用いた非線形波動変調に基づく大型構造物の接触型損傷検出

      科学研究費若手研究   2020年04月 ~ 2022年03月

  • 自励駆動型超音波を用いた非線形波動変調に基づく接触型損傷の検出

     科学研究費若手研究   2018年04月 ~ 2020年03月

 

学部講義等担当 【 表示 / 非表示

  • 人間探求学(機械システム)   2019年04月 ~ 現在

  • 機械工学基礎実験   2019年04月 ~ 現在

  • 機械設計演習Ⅲ   2017年09月 ~ 現在

  • 機械力学Ⅱ   2017年09月 ~ 2018年03月

  • 機械システム工学実験Ⅰ   2016年04月 ~ 現在

全件表示 >>