%AFunaki, T
%AHayashi, S [Osaka University, Osaka (Japan). Faculty of engineering]
%D1996
%I;
%J
%K42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES, 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS, SHIPS, MECHANICAL VIBRATIONS, LEVELS, DISSIPATION FACTOR, ENERGY LOSSES, FLUIDS, VISCOSITY, FINITE ELEMENT METHOD, DAMPING, MATRICES, SCALE MODELS
%PMedium: ED; Size: pp. 253-261
%TFundamental study on the new method to estimate vibration level on a ship. Formulation of the damping matrix based on dissipation energy caused by fluid viscosity; Senpaku no shindo level suitei ni kansuru kisoteki kenkyu. Ryutai no nensei ni yoru san`itsu energy ni motozuku gensui matrix no teishikika
%XIt is known in estimating vibration characteristics of a ship that fluid range affects largely a structure. In order to analyze the compound vibration therein, a method was proposed, which estimates vibration levels without using the finite element method. However, the problem of mode decay ratio has not been solved. Therefore, this paper first describes a method to introduce an equivalent linear decay matrix. The paper then mentions difference in the decay effects due to fluid viscosity in a shallow and deep water regions. Furthermore, vibration levels in the deep water region were estimated in a model experiment to verify the estimation result. Under a hypothesis that two-node vibration in a rotating ellipse has displacement distributions in the deep and shallow water regions equivalent, and when a case of vibration in a layer flow condition is calculated, dissipation energy in the shallow region is larger than that in the deep region by about 26%. About 5% of the total dissipation energy is consumed at bottom of the sea. According to a frequency response calculation, estimated values for the response levels still differ from experimental values, although the trend that the vibration levels change can be reproduced. 6 refs., 15 figs., 2 tabs.
%0Miscellaneous
Japan Other: ON: DE97721531; TRN: 96:913853 NEDO Japanese