Reduction of vibration on shipboard by passive type dynamic absorber and rational optimization

Research Project

Project/Area Number	17K14892
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Naval and maritime engineering
Research Institution	National Institute of Maritime, Port and Aviation Technology
Principal Investigator	Taniguchi Tomoyuki 国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (20782460)
Project Period (FY)	2017-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000) Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Keywords	動吸振器 / 船内振動 / 最適設計 / 複素モード解析 / 最急降下法 / 感度解析 / 上部構造物の簡易振動解析 / 動振吸器 / 振動制御 / モード解析
Outline of Final Research Achievements	In order to reduce in-board vibration after construction, we focused on the dynamic absorber as an inexpensive device that does not require external power, and verified its design method and effects. In the case of applying the dynamic absorber to the vibration of ship superstructures, optimization using steepest descent method and sensitivity analysis based on complex modal analysis was constructed. And we also investigate the effect of plate thickness and dynamic absorber to minimize the vibration evaluation reference value based on the international standard from the numerical calculation results. In the case of local vibration, we installed the prototype of dynamic absorber on a real ship, and the possibility of reducing local vibration by dynamic absorber was confirmed from the measurement results.
Academic Significance and Societal Importance of the Research Achievements	本研究では複素モード解析と最急降下法に基づく最適化を構築しているが，最急降下法に必要な勾配情報を複素モード解析結果から理論的に導出しており，厳密解と一致する勾配値を最小限の計算により求めることが可能となった．また，実船において試作型の動吸振器を設置し，実測結果から振動を低減化できる可能性を確認しており，今後のさらなる実証実験により海事分野における振動問題解決への貢献につながる．