Offshore platforms are widely used to explore, drill, produce, storage, and transport ocean resources and are usually subject to environmental loading, such as waves, winds, ice, and currents, which may lead to failure of deck facilities, fatigue failure of platforms, inefficiency of operation, and even discomfort of crews. In order to ensure reliability and safety of offshore platforms, it is of great significance to explore a proper way of suppressing vibration of offshore platforms. There are mainly three types of control schemes, i.e., passive control schemes, semi-active control schemes, and active control schemes, to deal with vibration of offshore platforms. This paper provides an overview of these schemes. Firstly, passive control schemes and several semi-active control schemes are briefly summarized. Secondly, some classical active control approaches, such as optimal control, robust control, and intelligent control, are briefly reviewed. Thirdly, recent advances of active control schemes with delayed feedback control, sliding model control, sampled-data control, and network-based control are deeply analyzed. Finally, some challenging issues are provided to guide future research directions.

Recent advances in vibration control of offshore platforms

A review of vibration control methods for marine offshore structures

Experimental and numerical investigation of ventilated cavitating flow with special emphasis on gas leakage behavior and re-entrant jet dynamics

The dynamics of a toroidal bubble near a solid wall for a large part of stand-off parameters γ (γ=d/Rmax, d is the distance between the solid wall and the bubble centre at the moment of formation and Rmax is the maximum bubble radius) have been extensively studied, but some mechanics of a toroidal bubble are not completely clear, especially for the small stand-off parameters γ ≤ 0.8. In the present study, on the basis of the finite volume method, the Navier-Stokes equations with inviscid and incompressible assumption are directly solved using a staggered grid on the fixed grid. The dynamics of the toroidal bubble near the solid for different stand-off parameters (γ = 0.4, 0.6, 0.8, and 0.97, respectively) are simulated by a front tracking method. Initial conditions of numerical simulation are estimated through the Rayleigh–Plesset equation, based on the maximum size and collapse time of a spark-generated bubble. One of the numerical results is compared with a spark-generated bubble experiment, showing tha...

Numerical analysis of the jet stage of bubble near a solid wall using a front tracking method

Cavitation–structure interaction has become one of the major issues for most engineering applications. The present work reviews recent progress made toward developing experimental and numerical investigation for unsteady turbulent cavitating flow and cavitation–structure interaction. The goal of our overall efforts is to (1) summarize the progress made in the experimental and numerical modeling and approaches for unsteady cavitating flow and cavitation–structure interaction, (2) discuss the global multiphase structures for different cavitation regimes, with special emphasis on the unsteady development of cloud cavitation and corresponding cavitating flow-induced vibrations, with a high-speed visualization system and a structural vibration measurement system, as well as a simultaneous sampling system, (3) improve the understanding of the hydroelastic response in cavitating flows via combined physical and numerical analysis, with particular emphasis on the interaction between unsteady cavitation development and structural deformations. Issues including unsteady cavitating flow structures and cavitation–structure interaction mechanism are discussed.

Dynamics of cavitation–structure interaction

A study on the collapse of cavitation bubbles surrounding the underwater-launched projectile and its fluid–structure coupling effects

Experimental research on fatigue property of steel rubber vibration isolator for offshore jacket platform in cold environment

Experiment and numerical simulation on the characteristics of fluid–structure interactions of non-rigid airships

The invention discloses an offshore jacket type platform vibration isolated layer-piling rubber bearing that includes: layer-piling rubber, up flanged shaft, down flanged shaft, and location limited device that can avoid the moving of up and down flanged shaft. Several metal slices are founded at the two ends of the layer-piling and the inner. The slices at the two ends are fixed to the up flanged shaft and down flanged shaft by connecting fitting. And the up flanged shaft and down flanged shaft would be fixed by the location limited device. The invention conquers the disadvantage that the routine layer-piling rubber bearing has not enough intension. And it is simple structure and easy to dismantle and install.

Laminated rubber support for vibration isolation of offing guide conduit type platform

The invention discloses a lapping rubber support high main pressure shearing fatigue testing device which comprises flange, pressing bolt and pressure sensor, the lapping rubber support is fixed on the flange between the motion plate and side wall and is pressed tightly with the pressing bolt the pressing force of which is monitoring by the sensor. The invention acquires the dual direction shearing fatigue loading when adding pressure, and is able to perform the test with normal test machine. The invention is of simple structure and operation.

Liu Yubiao

Papers

A study on the collapse of cavitation bubbles surrounding the underwater-launched projectile and its fluid–structure coupling effects

Experimental research on fatigue property of steel rubber vibration isolator for offshore jacket platform in cold environment

Experiment and numerical simulation on the characteristics of fluid–structure interactions of non-rigid airships

Laminated rubber support for vibration isolation of offing guide conduit type platform

Laminated rubber support high-cycle press-shear fatigue performance testing device