2017 Fiscal Year Final Research Report
Evaluation of Nonlinear Ultrasonic Phenomena by Electromagnetic Acoustic Transducer with Large Amplitude Using Superconducting Magnet
| Project/Area Number |
15K13826
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
高木 敏行 東北大学, 流体科学研究所, 教授 (20197065)
三木 寛之 東北大学, 学際科学フロンティア研究所, 准教授 (80325943)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Keywords | 電磁超音波プローブ / 非線形超音波現象 / 超伝導マグネット |
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| Outline of Final Research Achievements |
In this study, superconducting electromagnetic acoustic transducer (EMAT) is developed to transmit strong ultrasound with controlled frequency and sound pressure of incident wave, which is expected as an effective experimental tool for mechanism study of nonlinear ultrasonic phenomena. Transmitted wave of this system was evaluated by laser Doppler vibrometer. The measured surface displacement was compared with numerical analysis of ultrasound by EMAT. The result of numerical analysis was in a good agreement with the experimental data, which indicate the developed superconducting EMAT can transmit a ultrasound with controlled sound pressure.
Nonlinear ultrasounds from fatigue crack specimens were measured by the superconducting EMAT. Generations of some higher harmonics from closed cracks are confirmed for and dependence of higher harmonics on input frequency is investigated.
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| Free Research Field |
機械工学
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