海洋输液立管涡激振动响应及其疲劳寿命研究

以FrancisBiolley改进的vanderPol尾流振子模型为基础,考虑管内流动流体和管外海洋环境荷载共同作用,建立了海洋立管涡激振动微分方程,用Hermit插值函数对立管微分方程进行离散,并用Miner理论对立管的疲劳寿命进行分析,通过编程和实例计算,分析了管内流速对涡激响应幅值和疲劳寿命的影响。结果表明,当管内流体流速变化使立管的固有频率接近漩涡脱落频率时,立管涡激振动响应将会增大,疲劳寿命将会显著减少。

VORTEX-INDUCED VIBRATIONS AND FATIGUE LIFE OF MARINE RISERS CONVEYING FLOWING FLUID

Based on Biolley‘s wake oscillator model, the differential equation for the response of the vortex-induced vibrations (VIV) of the riser is derived. The effect of the internal flowing fluid and the external marine environmental condition are taken into account. The effect of the internal flowing fluid on the response of VIV of the riser is studied using finite-element method. The fatigue life of the marine riser is analyzed by Miner’s theory. The effect of the internal flow velocity on the response of VIV and the fatigue life of the riser is analyzed. Results show that when the natural frequency of the riser is near the vortex shedding frequency due to the change of initial velocity, the response of the VIV will increase and the fatigue life of the riser will decrease greatly.