Journal of Dalian Maritime University >
2016 , Vol. 42 >Issue 2: 28 - 34
DOI: https://doi.org/10.16411/j.cnki.issn1006-7736.2016.02.005
Quantification study on safety degree of ship capsizing in stochastic waves
Received date: 2015-10-16
Revised date: 2015-12-03
Online published: 2015-12-03
To quantify safety problem of ship capsizing, the safety degree of a ship sailing in random waves was studied based on stochastic Melnikov function and phase space transport theory from the energy perspective. Considering the nonlinear damping moment, nonlinear righting moment ,as well as the random waves, a nonlinear single degree of freedom differential equation of ship rolling was established. The random wave-induced moment was transformed from time domain to frequency domain by using FFT, and the random Melnikov function and the rate of phase flux were extended to effects of navigation speed and heading angle. The safety degree of a ship against capsizing was quantified according to the statistical properties.Based on studying the parameters of a typical ship, the variation of rolling phase space transport rate in stochastic waves was investigated, and the effects of ship speed, heading angle and wave characteristic frequency were analyzed. Research results show that the Melnikov function and random phase space transport theory are available to quantify the safety degree of a ship against capsizing, and then to provided beneficial reference for the further investigation on ship stability criteria.
ZHANG Jian-wei , WU Wan-qing , HU Jun-quan . Quantification study on safety degree of ship capsizing in stochastic waves[J]. Journal of Dalian Maritime University, 2016 , 42(2) : 28 -34 . DOI: 10.16411/j.cnki.issn1006-7736.2016.02.005
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