Study on Dynamic Strength and Vibration of High Speed Ships.
Grant-in-Aid for Co-operative Research (A)
|Allocation Type||Single-year Grants|
|Research Institution||Kyushu University|
OHTAKA Katuo Kyushu University, Faculty of Eng'g, Professor, 工学部, 教授 (80194182)
MORI Masahiro Nagasaki Institute of Technology, Professor, 教授 (80140937)
MICHIMOTO Jun-ichi College of Coast Guard, Associate Professor, 助教授 (80106806)
GOUDA Kunio Tsukuba Univ., Structure Division, Professor, 構造系, 教授 (40134209)
MAEDA Masahiro Kyushu Univ., Faculty of Eng'g, Research Assistant, 工学部, 助手 (70173713)
YASUZAWA Yukitaka Kyushu Univ., Faculty of Eng'g, Associate Prof., 工学部, 助教授 (10191123)
|Project Period (FY)
1990 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥13,300,000 (Direct Cost : ¥13,300,000)
Fiscal Year 1991 : ¥5,100,000 (Direct Cost : ¥5,100,000)
Fiscal Year 1990 : ¥8,200,000 (Direct Cost : ¥8,200,000)
|Keywords||Ship Strength / Vibration / Stiffened Plate / High Speed Ship / Submerged Structure / 船体構造 / 強度 / パワ-フロ-法|
A. Calculation procedure of longitudinal strength of thin-walled ship has been made which include the effect of shear lag. By this method calculation are made for semi-submersible hydrofoil catamaran and the existence of additional stress near the foil strut has been found in addition to the stress by ordinary beam theory.
B. Simplified calculation method for two-dimensional structures has been developed through combination of finite element method and transfer matrix method.
C. Dynamic strength of internal structural members against shock load is examined by theory and experiment, and the effect of setting angle between plate and stiffener on the strength has been clarified.
D. Vibration characteristics of submerged stiffened plate are investigated under the action of inpla ne load and initial deflection. The following results are obtained.
(1) Vibratory characteristics of the stiffened plate are sensitive to the initial deflection and inp lane load. Effect of initial deflection tends to increase, whereas that of inplane load decrease frequency, the trade-off of which decides the frequency of each structure. Change of frequency mentioned above has close relation to the buckling load and buckling mode shape of plates between stiffeners.
(2) Effect of entrained water on the natural frequency and mode shape has little to do with the init ial deflection and inplane load.
(3) Irregular initial deflection and irregular spacing of stiffeners tends to change the vibratory characteristics considerably, especially mode shapes.
E. Method to identify the vibratory characteristic matrix from measured data has been developed, whic h can be used for high-frequency vibration of high-speed ships.
Research Output (18results)