Vibration Analysis of High Speed Semi-Submergeble Catamaran

Abstract

This report deals with a method for the natural vibration analysis of high speed semi-submergeble catamaran which is made up of two cylindrical lower hulls, struts and upper deck.
The exact evaluation of added mass of water is inevitable to estimate the natural frequencies for such a structure, because vibration modes are fully three dimensional and are much different from the ordinary ship hull vibration modes.
Therefore the authors present here a method to compose a three dimensional added mass matrix by use of J factor, which is well known as a three dimensional correction factor.
The exciting tests of the experimental model were carried out, and the measured results showed a fairy good agreement with the calculated values obtained by the proposed method.