Model test of a concrete TLP for Gulf of Mexico
This paper describes the set-up and key results of a concrete TLP model test program performed at Offshore Technology Research Center (Texas) in January, 1994 by Aker Gulf Marine. The Concrete TLP had a deck weight of 26,000 short tonnes, the water depth was 3,000 feet and the environment was typical for Gulf of Mexico. The main focus was to measure resonant tendon loads as no practical and reliable tools to estimate higher order load effects (ringing and springing) has been available. The extreme condition tendon results showed significant high frequency content which must be accounted for in design. Although difficult to distinguish between ringing and springing responses, ringing as defined herein, was not observed in any of the tests. Increased tendon stiffness and increased vertical center of gravity does not affect the total tendon tension significantly i.e. combined wave frequency and high frequency tensions. The maximum horizontal offset was estimated to 9% of the water depth (278 feet). Four moderate seastates were run to estimate relative tendon fatigue damage for the various sensitivity cases. The results show that reduced TLP natural period does not necessarily increase the fatigue life due to combined springing and first order response. The measurements also showed that the high center of gravity case increased the tendon fatigue life for the lowest sea states, but the effect was reduced for moderate sea states beyond a certain level. Both Rainflow Cycle counting and standard methods for calculating fatigue are presented.
- OSTI ID:
- 39216
- Report Number(s):
- CONF-950254--
- Country of Publication:
- United States
- Language:
- English
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