Abstract
The aim of this paper is to establish a simple approach to experimentally study the mooring line damping in shallow water, where snap loading may occur more frequently. Experimental measurements were conducted in a wave basin at a scale of 1:50, which corresponds to a full scale of 28 m water depth. A chain made by stainless steel was used, and the tension force at the fairlead was measured by tension gages. Moreover, the line geometry, touchdown point speed, and mooring line velocity were derived from image processing techniques. Surge motions at fairlead were driven from a programmable wavemaker. Regular surge motions with different frequencies and pretensions were tested in this system in order to investigate the quasi-static and dynamic behaviors of the mooring chain. In the quasi-static test, the mooring line keeps a typical catenary shape, and its indicator diagram exhibits a smooth-closed curve. In the dynamic test, the mooring line is fully lifted from the seabed, and it cyclically goes through the stage of semitaut and fully taut. We successfully reproduced a snap event in the laboratory scale, and the resulting mooring line damping can considerably increase in this manner. Two criteria for snap event were examined, and both of them were verified by the experiments.
| Original language | English |
|---|---|
| Article number | 051603 |
| Journal | Journal of Offshore Mechanics and Arctic Engineering |
| Volume | 141 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 2019 Oct 1 |
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All Science Journal Classification (ASJC) codes
- Ocean Engineering
- Mechanical Engineering
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An Experimental Study of Mooring Line Damping and Snap Load in Shallow Water. / Hsu, Wen Yang; Chuang, Tzu Ching; Yang, Ray-Yeng; Hsu, Wei Ting; Thiagarajan, Krish P.
In: Journal of Offshore Mechanics and Arctic Engineering, Vol. 141, No. 5, 051603, 01.10.2019.Research output: Contribution to journal › Article
TY - JOUR
T1 - An Experimental Study of Mooring Line Damping and Snap Load in Shallow Water
AU - Hsu, Wen Yang
AU - Chuang, Tzu Ching
AU - Yang, Ray-Yeng
AU - Hsu, Wei Ting
AU - Thiagarajan, Krish P.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - The aim of this paper is to establish a simple approach to experimentally study the mooring line damping in shallow water, where snap loading may occur more frequently. Experimental measurements were conducted in a wave basin at a scale of 1:50, which corresponds to a full scale of 28 m water depth. A chain made by stainless steel was used, and the tension force at the fairlead was measured by tension gages. Moreover, the line geometry, touchdown point speed, and mooring line velocity were derived from image processing techniques. Surge motions at fairlead were driven from a programmable wavemaker. Regular surge motions with different frequencies and pretensions were tested in this system in order to investigate the quasi-static and dynamic behaviors of the mooring chain. In the quasi-static test, the mooring line keeps a typical catenary shape, and its indicator diagram exhibits a smooth-closed curve. In the dynamic test, the mooring line is fully lifted from the seabed, and it cyclically goes through the stage of semitaut and fully taut. We successfully reproduced a snap event in the laboratory scale, and the resulting mooring line damping can considerably increase in this manner. Two criteria for snap event were examined, and both of them were verified by the experiments.
AB - The aim of this paper is to establish a simple approach to experimentally study the mooring line damping in shallow water, where snap loading may occur more frequently. Experimental measurements were conducted in a wave basin at a scale of 1:50, which corresponds to a full scale of 28 m water depth. A chain made by stainless steel was used, and the tension force at the fairlead was measured by tension gages. Moreover, the line geometry, touchdown point speed, and mooring line velocity were derived from image processing techniques. Surge motions at fairlead were driven from a programmable wavemaker. Regular surge motions with different frequencies and pretensions were tested in this system in order to investigate the quasi-static and dynamic behaviors of the mooring chain. In the quasi-static test, the mooring line keeps a typical catenary shape, and its indicator diagram exhibits a smooth-closed curve. In the dynamic test, the mooring line is fully lifted from the seabed, and it cyclically goes through the stage of semitaut and fully taut. We successfully reproduced a snap event in the laboratory scale, and the resulting mooring line damping can considerably increase in this manner. Two criteria for snap event were examined, and both of them were verified by the experiments.
UR - http://www.scopus.com/inward/record.url?scp=85061825882&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85061825882&partnerID=8YFLogxK
U2 - 10.1115/1.4042535
DO - 10.1115/1.4042535
M3 - Article
AN - SCOPUS:85061825882
VL - 141
JO - Journal of Offshore Mechanics and Arctic Engineering
JF - Journal of Offshore Mechanics and Arctic Engineering
SN - 0892-7219
IS - 5
M1 - 051603
ER -