Citation

Luo Z, Cai M. China Saf. Sci. J. 2019; 29(7): 6-11.

Copyright

(Copyright © 2019, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2019.07.002

PMID

unavailable

Abstract

This research is carried out in order to improve the effectiveness of predicting the VIV of deep-water risers under the collective action of multiple factors. Firstly, based on Euler-Bernoulli beam bending theory and improved Van Der Pol wake oscillator equation, the VIV predication model of marine risers was established considering the effects of internal fluid flow and cross-flow (CF) and coupled in-line (IL), a differential equation was derived by using hermit interpolation function, and Newmark-β method was used to solve the displacement of risers in time domain through iterative solution. Then a VIV experiment was conducted to verify the prediction model. Finally, the effects of sea current flow velocity, internal and external flow velocity and top tension on VIV characteristics of deep-water risers were discussed. The results show that the vibration frequency and amplitude of a riser will increase as the sea current velocity increases, the natural frequency of risers may be reduced to the range of lock frequency along with the increase of internal flow velocity, accelerating the fatigue failure of risers, and influence of internal flow is obviously suppressed by the top tension, the two-way coupling effect should be given sufficient attention in the vibration analysis of risers. © 2019 China Safety Science Journal. All rights reserved.

Language: zh