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建立了深水钻井隔水管在平台升沉运动作用下的参激振动控制方程;利用振型叠加法将控制方程转化成马蒂厄方程形式,并用摄动法对马蒂厄方程进行求解;考虑海水的阻尼作用,得到了隔水管参激振动的马蒂厄不稳定区。最后对参激振动方程进行了实例求解,得到了参激振动下的隔水管位移,并在此基础上对参激振动的稳定性及隔水管强度进行了分析。结果表明:在给定的平台升沉周期与升沉振幅条件下,隔水管外径、壁厚、顶张力的变化均有可能引发隔水管产生参激共振;在不产生参激共振的情况下,隔水管Mises应力随隔水管外径与壁厚的增大而减小,随顶张力与升沉补偿装置轴向刚度系数的增大而增大;最大Mises应力均出现在隔水管顶部,沿水深近似成线性分布。
The parametric vibration governing equation of deepwater drilling riser under platform heave motion is established. The governing equations are transformed into the form of Mathieu equation by the modal superposition method, and the Mathieu equation is solved by perturbation method. Considering seawater The damped action of the riser has been solved. Finally, the parametric vibration equation is solved by examples. The displacement of the riser under parametric vibration is obtained. Based on the analysis, the stability of the parametric vibration and the riser strength are analyzed. The results show that the variation of the outer diameter, the wall thickness and the top tension of the riser may lead to the ghosting resonance of the riser at given platform heave period and heave amplitude. In the absence of parametric resonance , Mises stress of riser decreases with the increase of riser diameter and wall thickness, and increases with the increase of axial stiffness coefficient of riser and heave compensation device. The maximum Mises stress appears at the top of riser along The water depth approximates a linear distribution.