| Project/Area Number |
15560400
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Hokkaido University |
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Principal Investigator |
TAKASHI Obata Hokkaido University, Graduate School of Engineering, Research Associate, 大学院・工学研究科, 助手 (20214215)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | infrastructures / health monitoring / maintenance / three-dimensional monitoring / sound monitoring / AE monitoring / モニタリング / 非接触動的変位測定 / 音響測定 / フラクタル次元解析 |
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| Research Abstract |
In recent years, long-lived active use of infrastructures has become a very important problem in all over the world as well as Japan. The damage identification of infrastructures based on monitoring data is the effective technique for the maintenance and rehabilitation of bridges, tunnels and so on. The purposes of this study are to establish a three-dimensional displacement measuring system using digital image processing and computer analysis for reduction of the cost of monitoring systems. And also investigate damage identification method by using sound and AE monitoring system for infrastructures.
It is considered that the three-dimensional camera monitoring system in this study is almost proper from the absolute value of displacement and natural vibration frequency of experimental results. As a result, it can be judged that the displacement and the number of excellence vibrations that has some accuracy are understood.
From the result of sound spectrogram, it is considered that the change of the frequency response and damping characteristic of sound data could be judged visually and simply. As for the fractal dimension, the significant change has appeared in comparison with non-damage and damaged condition. With the increase of damage, the values of fractal dimension have decreased. On the other hand, fourier spectrum from AS data is changed by each damage. From the results of coherence, the decrease of coherence in resonant frequency could be confirmed with the increase of damage. Therefore, it is considered that the monitoring methods in this study have possibility of damage identification on infrastructures.
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