非均匀流环境中悬浮隧道锚索动力响应分析

Dynamic Response Analysis of Submerged Floating Tunnel Cable in Non-Uniform Flow Environment

为研究非均匀流作用下悬浮隧道锚索动力响应,建立了锚索-管体耦合振动理论模型。基于Hamilton原理建立了指数型流场环境中悬浮隧道锚索-管体系统振动方程组,求解得到锚索的动力响应,分析了最大流速和锚索-管体频率比对动力响应的影响。结果表明:在非均匀流中,悬浮隧道锚索表现出多频振动的特点;随着流速的增大,锚索最大位移值并不随之增大,但会激发锚索高阶模态参与振动并发生主振模态的转换。当涡激升力频率接近锚索的某阶模态频率时,锚索会出现涡激共振,锚索最大位移值一般出现在主振模态的峰值处。锚索-管体频率比为2时,锚索会受到涡激振动和参数共振的联合作用。

To study the dynamic response of the submerged floating tunnel(SFT)cable under the action of non-uniform flow,a coupled vibration model of the cable and tube was established.The vibration governing equations for the SFT cable-tube system in an exponential flow field environment were established based on the Hamilton principle.The dynamic response of a SFT cable was obtained,and the effects of maximum flow velocity and frequency ratio of the tube and cable on the dynamic response were analyzed.The results show that in non-uniform flow,the SFT cable exhibits multi-frequency vibration.With the increase of flow velocity,the maximum displacement value of the cable does not increase,but the higher order modes of the cable can be stimulated to participate in the vibration and the main vibration mode conversion occurs.When the vortex excitation frequency is close to the modal frequency of the cable,the cable appears to have vortex resonance,and the maximum displacement value of the cable occurs at the peak of the main vibration mode.When the ratio of the tube mass frequency to the cable main vibration frequency is 2,the cable shows the combined effect of vortex induced vibration and parametric resonance.