| Project/Area Number |
04555110
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
土木構造
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| Research Institution | Osaka University |
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Principal Investigator |
KAWATANI Mitsuo Osaka Univ., Dept.of Civil Eng.Associate Professor, 工学部, 助教授 (00029357)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1992: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Vibration Control / Highway Bridge / Traffic-Induced Vibration / Hybrid Control System / Model Test / Dynamic Reaction Force |
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| Research Abstract |
Experimental results of dynamic response of highway bridges under a moving test vehicle show that frequency of girder's response increases with increasing of velocity of the test vehicle. Such dynamic response has transient properties, that is, amplitude and frequency change due to traveling of vehicle on bridges. It is difficult that this kind of traffic-induced vibration is controlled by TMD (Tuned Mass Damper) of passive type. In this study, hybrid control system combining merits of passive type and active type is developed. Natural frequency of a springmass system is adjusted to the first natural frequency of a model bridge. The mass is controlled by AC servomotor to follow the response of the bridge, which is measured by a accelerometer.
Dynamic tests of a model girder are carried out to show the effectiveness of the hybrid control system compared with a control by TMD.A model vehicle is made of four wheels, and moved at a constant speed by a inverter controlled AC motor. The natural frequency of the model vehicle is about 3Hz, that is adjusted to the first natural frequency of the model girder. In another case the natural frequency of the vehicle is about 4Hz. Dynamic response of the girder is estimated in terms of r.m.s. (root mean square) of a displacement and an acceleration at the span center and reaction forces at supports. Dynamic reaction forces are examined here in respect to environmental dynamic effects to nearby ground and buildings from the traffic-induced vibration of bridges. Values of r.m.s are more reduced by the hybrid control system compared with TMD.The reduced rates for the displacement are larger than those for the acceleration or the reaction forces.
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