基于双频激励预测深海钢悬链立管(SCR)Hill不稳定性,即参量共振问题.根据Vandiver理论,将SCR等效转化为顶张力立管(TTR),以多频叠加函数模拟真实外激励,基于多频激励动力学方程得到Hill方程.分析基于多频激励的特殊情形,即双频激励预测系统参量稳定性特性,并以此评估工程中SCR的Hill不稳定性.结果表明:多频激励更能准确预测实际外激励,其预测是探究SCR参量稳定性的关键,相应激励函数的选取决定SCR的设计安全.
Hill stability of deep-sea steel catenary riser (SCR) was predicted based on bi-frequency excita- tion. The SCR was transferred into top tensioned riser (TTR) based on Vandiver theory, the multi-fre- quency signal is proposed to simulate the stochastic tension fluctuation, and Hill equation was obtained ac- cording to the dynamic motion equation of TTR under multi-frequency excitation. The parametric stability characteristic of the SCR system under hi-frequency excitation, a typical case of multi-frequency, was pri- marily discussed, and hi-frequency excitation was used for practical engineering analysis. The results show that multi-frequency excitation can better predict real sea condition than single frequency, the prediction of real external excitation is vital to the parametric stability prediction of SCR, and the riser safety design requirements are determined by the corresponding form of excitation function chosen.