中文摘要：

建立了柔性杆件在非均匀流作用下的涡激振动响应预测模型,考虑了涡激振动锁频阶段流体附加质量的变化,以及振动响应和来流简缩速度的非线性关系。该模型通过经验公式结合迭代求解的方式,计算方便、速度快,避免了数值计算（CFD）的繁琐,较为适合于海洋工程实际应用。与试验和数值结果的比较表明采用该文提出的计算模型,可以更合理、准确地给出结构涡激振动响应。最后,结合实际平台参数,进行了柔性立管在非均匀流场的作用下的涡激振动响应分析,并研究了立管的预张力、流场分布等参数的影响。分析结果表明：随着立管张力和流场分布的改变,各阶模态锁频区域发生了变化,从而改变了结构的总体响应

英文摘要：

For the aim of improving the Wake-oscillator Model,an analytical model for vortex-induced vibration of flexible riser under non-uniform current is presented,in which the variation of added mass and the nonlinear relationship between amplitude response and the reduced velocity are considered. By means of empirical formula combining iteration computation,the improved analytical model can be conveniently implemented by computer code and has a simpler and faster computation process than CFD so as to be suitable to the application in practical engineering. This model is validated by comparing with experiments and numerical simulations. Our results show that the improved model can predict VIV （Vortex-Induced Vibration） response and lock-in range more accurately. At last,illustrative examples are given in which the amplitude of response of flexible riser experiencing VIV under action of non-uniform current is calculated and effects of riser tension and flow distribution along span of riser are explored. It is implied that with changes of tension and current distribution,lock-in domains of modes move along riser,thus the total responses of riser are synthesis of response for locked modes.