1999 Fiscal Year Final Research Report Summary
Study on High Cycle Vibration of Ship Structure
| Project/Area Number |
09555308
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
船舶工学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KAGAWA Koji Faculty of Engineering, Kyushu University, Professor, 大学院・工学研究科, 教授 (00253500)
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| Co-Investigator(Kenkyū-buntansha) |
TOYODA Kazutaka Faculty of Engineering, Kyushu University, Assistant, 大学院・工学研究科, 助手 (10274507)
MAEDA Kasahiro Faculty of Engineering, Kyushu University, Assistant, 大学院・工学研究科, 助手 (70173713)
YASUZAWA Yukitaka Faculty of Engineering, Kyushu University, Associate Professor, 大学院・工学研究科, 助教授 (10191123)
NISHIDA Hiroshi MHI Nagasaki RD Center, Senior Researcher, 長崎研究所, 主任研究員
FUJITA Kazunobu MHI Nagasaki RD Center, Research Project Manager, 長崎研究所, 主務研究員
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| Project Period (FY) |
1997 – 1999
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| Keywords | Stiffened Plate / Optimal Design / Structure Modification / Marine Propulsion / High Cycle Vibration / Fluid-Structure Coupling / Contribution Factor / Coupled Vibration |
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| Research Abstract |
A ship hull structure is a much complicated steel structure which consists of many stiffened this plates. High cycle vibrations in the ship structure are originated by the propulsion such as a propeller and a main engine and are easily transmitted to the local structures such as a superstructure and water tanks. Fatigue damages can also be sometimes observed in these tanks which seemed to be caused by resonance. In order to make prevention of these problems, following studies have been carried out.
1. We developed new method that is to analyze (1) Dynamic interaction between ship hull and main engine by means of substructure approach, (2) Vibratory response considering the influence of moving parts in engine, and (3) Contribution of exciting forces to the vibratory response. We proved that the characteristics of the exciting force from the shaft is much influenced.
2. The vibration characteristics of the stiffened plate is examined, and some main vibration modes are studied. In the mult-level optimization, the dynamic characteristics of the stiffened plate is changed by the proposed simplified equation. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate.
3. Thin walled tank located near the engine or propeller are strongly affected by the added mass of containing water. We have developed a numerical tool of vibration analysis using finite elements for plates and boundary elements for fluid. The effect of added mass of containing water and structural constraint between panels on the vibration characteristics are investigated numerically. Especially natural frequencies and hydrodynamic pressure of breath mode of the water tank are focused on and clarified.
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Research Products
(6 results)
