| Project/Area Number |
07305065
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 総合 |
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| Research Field |
海洋工学
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| Research Institution | University of Tokyo |
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Principal Investigator |
SUZUKI Hideyuki University of Tokyo, Department of Naval Architecture and Ocean Engineering, Associate Professor, 大学院・工学系研究科, 助教授 (00196859)
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| Co-Investigator(Kenkyū-buntansha) |
YASUZAWA Yukitaka Kyushu University, Naval Architecture and Marine System Engineering, Associate P, 工学部, 助教授 (10191123)
FUJIKUBO Masahiko Hiroshima University, Department of Naval Architecture and Ocean Engineering, As, 工学部, 助教授 (30156848)
HATTORI Yoichi Kanazawa Institute of Technology, Department of Mechanical Engineering, Professo, 工学部, 教授 (40198768)
OKA Noriaki University of Tokyo, Department of Naval Architecture and Ocean Engineering, Ass, 大学院・工学系研究科, 助手 (80010891)
YOSHIDA Koichiro University of Tokyo, Department of Naval Architecture and Ocean Engineering, Pro, 大学院・工学系研究科, 教授 (90010694)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1996: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Keywords | Very Large Floating Structure / Elastic Response / Pontoon Type / Semi-submersible Type / Matching / Resonance / Natural Frequency / Elastic Foundation / 半潜式海洋構造物 |
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| Research Abstract |
A very large floating structures is a promising solution to satisfy the demand for flat land in Japan. Shallow waters suitable for reclamation have been already reclaimed, and deeper waters where reclamation is not easy must be utilized.
The general dynamic response characteristics of a very large floating structure in the order of kilometers were analyzed and discussed using simplified numerical models. The models are of an anisotropic plate or beam on an elastic foundation. This modeling is a simple one but gives a general understanding and perspective of the elastic response characteristics of a very large floating structure. Based on the understanding obtained from this model, structural planning and design which utilize the advantages and avoid the disadvantages of the structure become possible.
It was shown that the natural frequencies of the eigenmodes are higher than the natural heave frequency of the structure. The matching of the elastic mode and the spatial wave excitation pat
… More
tern, in addition to the coincidence of natural frequency and wave frequency, is necessary for the divergent resonance response. The characteristic length, which is a useful measure to juddge the deformation of the structure, is defined from the bending rigidity and the spring constant of the restoring force. For waves whose wavelength is longer than the characteristic length, the structure is relatively flexible and shows deformation on the wave slope. For waves of shorter wavelength than the characteristic length, the structure is relatively rigid and shows little deformation.
A new pontoon type very large floating structure was proposed. The outer edge were modified and utilized as a control device to improve response characteristics of overall response of the structure. The improved response was confirmed by a series of calculations. The method of analysis used was to connect segmentally the analytical solutions of a uniform beam on an elastic foundation.
The response of very large floating structure under take-off and landing loads of aircrafts was evaluated and the effect of interaction between the aircraft and the structure was discussed. The accuracy of calculation method was confirmed by experiment with small clastic experimental model. From the calculation, it can be said that net increase of resistance on the aircraft induced by the structure is very small. Less
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