中文摘要：

为了分析两种边界条件下水下悬浮隧道锚索在均匀流作用下振动的稳定性问题,建立了锚索的振动方程并用伽辽金法对其进行简化,采用Lyapunov指数法判断了锚索涡激振动的稳定性,同时分析比较了阻尼比、弯曲刚度、锚索跨度、均匀流速和涡激频率对不同边界条件下锚索振动稳定性的影响。研究结果表明：随着均匀流速的增加,两种边界条件下的锚索都逐渐从稳定的状态转变为不稳定状态;锚索振动系统的弯曲刚度、阻尼比越大,锚索越容易趋于稳定状态;两种边界条件下的涡激频率与锚索一阶固有频率接近时,会发生涡激共振现象,锚索最容易失稳;随着均匀流速的增加,两种边界条件下锚索的不稳定区域都逐渐增大,但相比铰支边界而言,组合滑动边界条件下锚索的不稳定区域更大一些。

英文摘要：

In order to analyze the vibration stability of submerged floating tunnel tether under two different boundary conditions,the vibration equation of tether was set up. The equation was simplified by Galerkin method. The vibration stability of tether was judged by Lyapunov exponent method. Effects of damping ratio,bending stiffness and span of tether,current velocity and vortex-induced frequency on vibration stability of tether were analyzed and compared under different boundary conditions. It may be concluded that tether is been gradually from stable state to unstable state as the current velocity increases under two different boundary conditions. The tether tends to be stable as the damping ratio,bending stiffness of tether increases,when the vortex-induced frequency under two different boundary conditions is close to the tether. It will occur vortex-induced resonance and the tether is easy to be unstable,and the unstable region expands gradually as the current velocity increases under two different boundary conditions,but the unstable region is larger which under the combination sliding boundary.