Cross-bi-spectral analysis of high-frequency tether force signals from TLP model tests: A case study
- Norwegian Marine Technology Research Inst. A/S, Trondheim (Norway)
Tether tension records from model tests with a tension-leg-platform in irregular waves are analyzed with the purpose of evaluating the capability of the 2nd-order model to represent the high-frequency (HF) non-linearities. A high-pass filter is applied to separate out the HF contents of the tension signal. The 2nd-order sum-frequency content of the non-linear process is extracted by means of cross-bi-spectral analysis combined with 2nd-order reconstruction and comparison with the original tether tension. A description of the procedure is given. The results show that in a beam sea condition with low waves most of the signal is recognized as a 2nd-order response with respect to the waves. In a quartering sea condition with high waves, however, the average 2nd-order contribution to the HF dynamics is reduced to 50%, and in the extreme response events it is as low as 30%. Thus for a proper description of extreme HF responses on the actual TLP, a mechanism different from 2nd-order loading must be considered.
- OSTI ID:
- 403092
- Report Number(s):
- CONF-940409-; ISBN 1-880653-10-9; TRN: IM9651%%127
- Resource Relation:
- Conference: 4. international conference on offshore and polar engineering, Osaka (Japan), 10-15 Apr 1994; Other Information: PBD: 1994; Related Information: Is Part Of The proceedings of the fourth (1994) international offshore and polar engineering conference. Volume 1; Chung, J.S. [ed.] [Colorado School of Mines, Golden, CO (United States)]; Natvig, B.J. [ed.] [Aker Engineering A/S, Oslo (Norway)]; Das, B.M. [ed.] [Southern Illinois Univ., Carbondale, IL (United States)]; PB: 649 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Model test of a concrete TLP for Gulf of Mexico
A proposed ringing analysis model for higher order tether response