斜拉桥三维拉索风雨激振准两自由度模型

Quasi 2-DOF Model for Rain Wind Induced Vibration of 3-D Cables of Cable Stayed Bridges

拉索风雨激振是当前桥梁工程和风工程界非常关注的研究课题。过去用于测量带人工水线的拉索模型都是二维的,所建立的理论模型也是建立在二维拉索气动力的基础上的。本文基于带人工水线三维拉索模型试验得到的气动力,建立了三维拉索风雨激振的准二自由度运动微分方程,讨论了运动方程中各种参数的取值,采用数值求解方法计算了拉索风雨激振振幅。计算结果和三维拉索人工降雨试验结果的对比表明,本文方法能较好地描述三维拉索风雨激振的特征。

Rain wind induced cable vibration in cable stayed bridges is presently a problem of great concern in communities of bridge engineering and wind engineering. The 2 dimensional cable models with artifical rivulets have been tested in wind tunnels for obtaining the aerodynamic forces on the cables. The theoretical models for rain wind induced vibration of 2 D cables have been accordingly proposed on the base of 2 D aerodynamic forces. A new quasi 2 DOF theoretical model for rain wind induced vibration of 3 D cables was established based on the aerodynamic forces of 3 D cables. The values of some important parameters were discussed. The vibration amplitudes of 3 D cables were computed, and then compared with those from another wind tunnel test on a cable model with the same parameters as those in this computation but under raining simulation. The comparison verifies verifies the present theoretical model.