Numerical calculation method of mooring damping

Abstract

The invention provides a numerical calculation method of mooring damping. The damping contribution of a mooring system as a motion response to a marine floating structure can be accurately calculated.Firstly, a lumped mass method or a nonlinear finite element method is utilized to calculate the motion response of a mooring line under the top forced displacement excitation, and the position and velocity of each micro-segment node of the mooring line are obtained; secondly, the angle, normal velocity and tangential velocity of each micro-segment unit are calculated, and normal and tangential drag forces performed on the mooring line are solved based on a Morison formula; finally, the work of the drag forces performed on each micro-segment of the mooring line within a motion cycle is calculated, integration is conducted along the whole length of the mooring line, the energy consumed by the mooring line within one cycle can be obtained, and therefore an equivalent linearized mooring damping coefficient is obtained. The calculation method of mooring damping is high in precision, meanwhile, not only can the whole damping contribution of the mooring line be evaluated, but also the contribution ratio of any length segment in the mooring line to the whole damping can be studied, and a reference is provided for the design of the mooring system.

Description

technical field [0001] The invention belongs to the application field of marine engineering, and relates to a method for calculating the damping of mooring lines of marine floating structures, which is applicable to the damping analysis of single-component and multi-component mooring lines. Background technique [0002] When calculating and analyzing the mooring system of marine floating structures, it is important to study the mechanism of mooring damping and correctly calculate the damping contribution of the mooring system to the motion response of marine floating structures, which is very important for accurately predicting the motion response of floating structures and the stress on mooring lines. significance. For the research of mooring damping, there are mainly three methods at present: quasi-static analysis method, time-domain finite element indicator diagram method and model test method. The quasi-static analysis method assumes that the mooring line is in a quasi-...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the existing mooring damping calculation method cannot accurately evaluate the contribution of any segment to the overall damping, and combine the respective advantages of the quasi-static analysis method and the finite element indicator diagram method to propose a new mooring method based on dynamic analysis. Accurate Calculation Method of Damping

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