单频与多频激励下深海TTR立管参激特性分析

Analysis of Parametric Excitation Characteristics of Deep-sea Top Tensioned Riser under Multi-frequency Excitation

为深入研究深海TTR立管参激振动的本质特征,论文基于单自由度马修方程理论,利用摄动法研究了TTR立管在单频激励下的稳定性。基于复杂梁弯曲理论推导了希尔方程,分析对比了立管在单频和多频激励下的稳定性和各工况下的动态响应,以及极端海况下立管的振动特性,提出了一种引入额外阻尼来抑振的措施。得到了可以用来预报TTR参激稳定性的希尔稳定性图,立管在极端海况下希尔不稳定性可能会被激发,且激发的模态数增加。

In this paper,Mathieu equation of single degree of freedom and the perturbation method are applied to study the stability of a top tensioned riser(TTR)under single frequency excitation.The Hill equation is derived based on the bending theory of complex beams,and the stability of the riser under single-frequency and multi-frequency excitation is analyzed and compared.Vibration characteristics of the riser under extreme sea conditions are revealed,and vibration suppression measures are proposed.The Hill stability map is obtained for predicting the TTR’s parametric stability.Hill instability may be excited and the number of exciting modes may be increased in extreme sea conditions.