悬浮隧道管体运动对锚索涡激振动的影响

Effect of Submerged Floating Tunnel Tube Motion on Vortex-Induced Vibration of Cables

根据锚索式悬浮隧道的运动特性,将锚索假设为两端铰接的非线性梁模型,在海流作用下,锚索会产生顺流向与横流向的涡激振动。当海流方向和管体轴向存在夹角时,管体运动可简化为作用在锚索上部端点的质点运动,并将质点运动沿锚索坐标系方向逐一分解。根据Hamilton原理建立锚索三向振动方程,并通过Galerkin方法和Runge-Kutta方法对该方程进行求解,选取典型悬浮隧道的结构进行数值分析。结果表明:当锚索上部端点的输入频率与锚索固有频率的比值为整数时,锚索会发生共振现象;如上部端点除锚索轴向方向外的某一方向质点运动与锚索振动方向一致,则锚索在该方向上的振动会出现显著变化,而对另一方向振动的影响较小;在多数情况下,锚索振动平衡位置的偏离与上部端点所输入的运动频率有紧密联系,但与幅值联系不大。

According to the motion characteristics of the submerged floating tunnel,the cable is assumed as a non-linear beam model hinged at both ends.The angle is between the current and the tube,the tube motion can be reduced to a three-degree-of-freedom mass motion,which corresponds to the cable coordinate system.The three-way vibration equation of the anchor cable is established according to Hamilton's principle,and solved by the Galerkin and Runge-Kutta methods.The results show that when the ratio between the cable upper point frequency and the cable intrinsic frequency is an integer,the cable resonates.If the mass motion direction is the same as the cable vibration,then the vibration significant changes,while it has less influence in the other direction.In most cases,the deviation from the equilibrium position of the cable is related to the cable upper point frequency,without the amplitude.