中文摘要：

涡激振动是立管发生破坏的主要原因之一,深海立管自重大、柔度高、顶部张力集中等会导致出现新的动力特性.为预报深海立管涡激振动并揭示其动力特性,考虑立管自重影响及线性剪切流,本文建立立管涡激振动方程,基于VanderPol尾流振子模型,采用有限差分法计算立管的振动响应,并设计涡激振动试验进行验证,最后研究流速及顶张力对立管涡激振动的影响.结果表明：流速越大,立管涡激振动频率越高,振动应力越大;同等流速下,顶张力越大,立管涡激振动主频率变化不大,但振动位移增大,振动应力减小.

英文摘要：

Vortex-induced vibration （ VIV） is one of the main causes of the destruction of marine risers. The dynam-ic VIV characteristics of deepwater risers may include their large self- weight, high flexibility, and the stress con-centration caused by top tension, among others. In order to predict the VIV of deepwater risers and determine their dynamic characteristics, we established a governing equation of VIV in risers that takes into account the self-weight and linear shear flow. We used the finite difference method to calculate the dynamic response of a riser, based on Van der Pol wake-oscillator model. We then conducted a VIV experiment to verify the prediction model. In this study, we discuss the effects of flow velocity and top tension on the VIV of deepwater risers. Our study results show that the vibration frequency and vibration stress of a riser increases, as the flow velocity increases. Under the same flow conditions, the vibration displacement of a riser increases and the vibration stress decreases as the top tension increases. The dominant frequency of a riser is hardly influenced at all by the top tension.