基于重叠网格法的斜拉索涡激振动分析

Analysis on Vortex Induced Vibration of Stay Cable Based on Overset Mesh

斜拉索为细长结构,其阻尼比较小,容易发生涡激振动。为研究斜拉索涡激振动响应特性,结合CFD方法和重叠网格技术,对斜拉索二维模型进行了研究。利用CFD软件Fluent求解二维不可压缩黏性流体Navier-Stokes方程,并通过Fluent提供的UDF接口,嵌入自编Newmark-β法程序,求解两自由度结构动力响应方程。研究结果表明:相较于低质量比涡激振动响应,斜拉索涡激振动振幅较低,但其可能造成的疲劳破坏不容忽视;斜拉索涡激振动的锁定区间很短,对风速的变化比较敏感;斜拉索运动轨迹也更加丰富,不再是单一的“8”字形运动。

The stay cable was a slender structure with relatively low damping.It was prone to vortex-induced vibration.Combined with the CFD method and overset mesh,the vortex-induced vibration response characteristics of stay cable were studied.The CFD software Fluent was used to slove the Navier-Stokes equations of two-dimensional incompresible viscous fluids,and the UDF interface provided by Fluent and embed the self-edited Newmark-βmethod program were used to solve the dynamic response equations of the two-degree-of-freedom structure.The research results showed that,compared with the low-mass ratio vortex-induced vibration response,the vortex-induced vibration amplitude of the stayed cable was lower,but the possible fatigue damage could not be ignored;the lock-up interval of the stayed cable vortex-induced vibration was very short,the trajectory of the stay cable was also richer,no longer a single“8”-shaped movements.