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
✍ Scribed by Jong-Shyong Wu; Mang Hsieh
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 424 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0029-8018
No coin nor oath required. For personal study only.
✦ Synopsis
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 frequencyresponse 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 m ah and I ap . 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 (C V and C P ) 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.