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针对大跨度斜拉桥拉索大幅振动控制问题,考虑由于索的初始垂度、大位移而引起的几何非线性因素的影响,同时考虑拉索与桥面连接条件和边界条件的影响,建立了拉索在参、强联合激励作用下的面内非线性振动方程。运用多尺度摄动方法,对其进行求解,以目前最长拉索为例,研究拉索初始索力的变化对其大幅振动的影响。研究结果表明:增加斜拉索的初始张拉力,将使索表现出的软弹簧特性变为硬弹簧特性,同时,拉索的振幅最大值对应的激励频率与拉索固有频率比值将由小于2改变为大于2。
Considering the influence of geometrical nonlinear factors caused by the initial dip and large displacement of the cables, considering the influence of the connection between the cable and the bridge deck and the boundary conditions, aiming at the problem of large amplitude cable vibration control of long-span cable-stayed bridges, In - Plane Nonlinear Vibration Equation of Cables under Parametric and Strong Joint Excitation. The multi-scale perturbation method is used to solve the problem. Taking the present longest cable as an example, the influence of initial cable force on its large amplitude vibration is studied. The results show that increasing the initial tension of the stay cable will change the soft spring characteristic exhibited by the cable into a hard spring characteristic. At the same time, the ratio of the excitation frequency corresponding to the maximum amplitude of the cable to the natural frequency of the cable will be changed from less than 2 Is greater than 2.