阻尼器对悬索桥吊索扭转振动控制效果的数值研究

刚性分隔器对悬索桥吊索各索股的相对振动可起到很好的控制效果，但吊索可能会发生较大的整体振动，包括平动和扭转振动.采用ANSYS有限元软件，以某桥的四索股吊索为工程背景，分别建立了3种索股-刚性分隔器-阻尼器计算模型，并进行了自由振动分析，研究了理想状况下的吊索扭转模态的无量纲阻尼比曲线特征，研究了阻尼器支架刚度、阻尼器刚度对阻尼器效率的影响.研究结果表明，四索股-刚性分隔器-阻尼器体系不同扭转模态的无量纲阻尼比曲线不重合，不同扭转模态的阻尼器设计不能采用同一条无量纲阻尼比曲线进行设计；随着阻尼器支架刚度的减小，能实现的最优扭转模态阻尼比减小，对应的最优阻尼系数也减小；随着阻尼器刚度的增大，能实现的最优扭转模态阻尼比减小，对应的最优阻尼系数线性增大.
The relative oscillation between the strands of the suspension bridge hangers could be effectively mitigated by means of rigid spacers, but the hanger-spacer system may experience overall translational or torsional vibrations. In this paper, based on a four-strand hanger of the Xihoumen Bridge, the ANSYS software was utilized to establish three kinds of computational models for the hanger-spacer-damper system, and a series of free vibration analyses were carried out to study the characteristics of the universal curve for the torsional modes considering the effects of support stiffness and damper stiffness. The results show that the universal curves are affected by the torsional modes, and a unified universal curve cannot be used for the design of the dampers for different torsional modes. The realizable maximum damping ratio for torsional mode and its corresponding damper coefficient reduce with the decrease of the support stiffness. However, the realizable maximum ratio for torsional mode decreases with the increase of the damper stiffness, but its corresponding damper coefficient increases.