Measure and Simulated Dynamic Response of a Jacket and a Large Jack-up Platform in North Sea

The Influence of Ship Collision Parameters on the Global Nonlinear Dynamic Response of a North-Sea Jack-Up Platform

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.4028190 ◽

2014 ◽

Vol 136 (4) ◽

Author(s):

M. R. Emami Azadi

Keyword(s):

Dynamic Response ◽

Dynamic Behavior ◽

North Sea ◽

Impact Energy ◽

Nonlinear Dynamic ◽

Side Impact ◽

Nonlinear Dynamic Behavior ◽

Ship Collision ◽

Vessel Impact ◽

Jack Up

In the present study, the influence of ship collision parameters related to vessel impact energy and also the impact scenario on the global nonlinear dynamic behavior of a three-leg jack-up platform is investigated. A North-Sea three-leg jack-up platform is studied as a case which is located in water depth of about 105 m. Nonlinear elastoplastic and hyperelastic type spring models are used for ship bow and broad-side impacts. A nonlinear elastoplastic type spud-can-soil interaction model is also applied. Loose sand to medium dense sand profile is considered at the sea-base. The effects of ship collision parameters such as ship mass and velocity, impact direction, hit point on jack-up as well as the spud-can-soil interaction are studied. For the first time, the supply vessel impact energy level far beyond 14 MJ as conventionally applied for ship-jack-up leg collision analysis (i.e., higher energy impact) has been also considered. The findings of this study indicated that the type of bow or broad-side impact as well as the spud-can-soil interaction may have considerable effects on the nonlinear dynamic behavior of the jack-up platform during ship collision. It is also found that ship collision in the direction of incident waves with mass of 5000 tons and impact velocity of 5 m/s displacement may have more profound effect on global dynamic response of the jack-up platform near ultimate collapse. It is also found in this research work that dynamic postimpact behavior of the jack-up platform may be greatly influenced by the combined action of extreme wave and current.

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Evaluating jack-up dynamic response using frequency domain methods and the inertial load set technique

Marine Structures ◽

10.1016/0951-8339(95)00006-r ◽

1996 ◽

Vol 9 (1) ◽

pp. 101-128 ◽

Cited By ~ 4

Author(s):

E.J. Greeves ◽

B.H. Jukui ◽

P.G.F. Sliggers

Keyword(s):

Dynamic Response ◽

Frequency Domain ◽

Inertial Load ◽

Frequency Domain Methods ◽

Jack Up

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An Analytical Procedure to Predict Transverse Vibration Response of Jack-Up Riser under the Random Wave Load

Shock and Vibration ◽

10.1155/2020/5072989 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Fengde Wang ◽

Wensheng Xiao ◽

Yanan Yao ◽

Qi Liu ◽

Changjiang Li

Keyword(s):

Dynamic Response ◽

Oil And Gas ◽

Beam Theory ◽

Random Wave ◽

Wave Load ◽

Main Component ◽

Gas Leaks ◽

Jack Up ◽

Euler Bernoulli Beam ◽

Transverse Response

Marine riser is a key equipment in offshore drilling operation, and failure of the riser can lead to drilling moratorium; in severe cases, it may cause oil and gas leaks. In this paper, the time-dependent boundary conditions of the riser and the randomness of wave load are considered to improve the calculation efficiency and accuracy of the dynamic response of the jack-up riser. Based on the Euler–Bernoulli beam theory, an analytical method to determine the response of the jack-up riser subjected to the random wave load was established by the Mindlin–Goodman method in the frequency domain, and an experiment was carried out to verify it. The research shows that transverse dynamic response is the main component of the transverse response of the riser, and the method proposed is feasible to calculate the transverse response of the riser.

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