Deep-sea platform mooring system parametric excitation-internal resonance coupled vibration analysis and control method

Abstract

The invention discloses a deep-sea platform mooring system parametric excitation-internal resonance coupled vibration analysis and control method. The method comprises the following steps of: (1) performing static analysis on a platform and a cable, and determining the inherent vibration property of the platform; (2) analyzing the influence of different wave heights and wave frequencies on the kinetic properties of the platform and a mooring coupling system by using the calculation result of the static analysis as a condition of kinetic analysis, and calculating the change of parametric excitation-internal resonance coupled motion amplitude of the platform through time; and (3) adjusting a ballast system of a hard bin and a soft bin in a parametric excitation-internal resonance coupled motion state, and changing the gravity center position and the buoyancy center position of a platform main body to adjust the inherent frequency ratio of heaving oscillation to pitching oscillation so that the pitching oscillation of the platform main body is inhibited. By using the method, the parametric excitation-internal resonance motion of the platform is controlled by changing the gravity center position and the buoyancy center position of the platform and destroying the dynamical conditions for producing parametric excitation-internal resonance under the condition of possibly unstable parametric excitation-internal resonance motion.

Description

technical field [0001] The invention relates to a deep sea platform parametric excitation-internal resonance coupling vibration analysis method and control technology, in particular to a deep sea platform mooring system parametric excitation-internal resonance coupling vibration analysis program and vibration control technology. Background technique [0002] In deep waters above 1,000 meters, classic SPAR platforms or truss-type SPAR platforms are used for oil exploitation, and the platform mooring system uses steel cables or polyester cables. The results of foreign experiments and engineering practice in recent years have shown that due to the characteristics of the platform structure, the heave and pitch modes of the platform form a 2:1 internal resonance relationship. When the amplitude of the main heave motion of the platform increases, the platform will The pitching motion loses stability and enters a large chaotic motion state, which is called parametric excitation-int...

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Problems solved by technology

[0004] The parametric excitation-internal resonance coupling motion characteristics of the deep-sea SPAR platform seriously threaten the safety of the platform operation, causing severe movement of the main body of the platform, sudden changes in the dynamic tension of the mooring line and large swings of the oil production riser, resulting in fatigue damage of the mooring line and the riser. Reduced life of mooring lines and risers

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