On the Behavior of Semisubmersible Platforms at Large Angles

Abstract

The main purpose of this paper is to present experimental results from model tests of a semisubmersib-Ie platform at large angles of list. Very little work has previously been done in this problem area, and hardly any of it has been published. Therefore, we entered our test programme for the following two reasons: To provide insight into the problem of a large list angle, and to see how far linear hydrodynamic theory could be used to predict the forces and motions of the platform. Both items are discussed in the paper.

Heave response of a floating vertical cylinder with built-in tuned mass damper

“…A possible explanation for the phenomenon is the occurrence of Benjamin-Feir instability in the wave tank. It is a hydrodynamic mechanism which leads to the appearance of subharmonic waves with frequencies lying between 0.7 to 0.9 times the old frequency, and the occurence of a clearly recognized beating or amplitude variation of the wave train (Huang et al, 1982). This beating has indeed been observed in the water surface elevation time history from the experiments.…”