An experimental method for determining the frequency-dependent added mass and added mass moment of inertia for a floating body in heave and pitch motions |
| |
| Authors: | Jong-Shyong Wu Mang Hsieh |
| |
| Institution: | Institute of Naval Architecture and Marine Engineering, National Cheng-Kung University, Tainan, 701, Taiwan, ROC |
| |
| Abstract: | Most of the existing relevant materials have been obtained from experiments, in which evaluating the added mass at the resonant frequency corresponding to the peak of a frequency-response curve obtained from the “forced” vibration analysis is the most popular technique. In this paper, a simple experimental method was presented where the “free” vibration responses instead of the “forced” ones were used to determine the values of mah and Iap. The main part of the experimental system is composed of a floating body (model) and a spring–shaft shaker. The “free” vibration of this main part was induced by imposing on it an initial displacement (and/or an initial velocity), and from the time histories of displacements information such as the “damped” natural frequencies, damping ratios, sectional added mass coefficients (CV and CP) were obtained. Since the displacements of the spring–shaft shaker are “translational” and those of the floating body due to pitch motions are “angular”, a technique for the transformation between the associated parameters of the two components of the main part was presented. |
| |
| Keywords: | Added mass Added mass moment of inertia Floating body (model) Spring– shaft shaker Time history Frequency-response curve |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
