Connecting cables with cross-ties to form a cable network is a viable solution for suppressing cable vibrations. The cross-ties need to be pretensioned to prevent them from being completely released and suffering from shocks during cable vibrations. However, most existing studies have ignored the cross-tie pretension for dynamic analysis. Therefore, this study investigates the effects of cross-tie pretension on in-plane dynamics of a cable network. The effect on cable tension forces and static profiles is first studied. Complex modal analysis is then performed to formulate the characteristic equation of a cable network considering small cable sag, cross-tie stiffness, and pretension, and dynamics of a two-cable network is discussed in detail. It is found that when the cross-tie is not connected to the bridge deck, the cross-tie could reduce the system frequency due to its pretension, particularly in modes where the vibration of the cable whose tension is reduced by the cross-tie pretension dominates. Nevertheless, when the cross-tie is connected to the ground, it seems to always increase system frequencies. Furthermore, simplified analyses are conducted based on the taut-string model of the cables considering cable tension force modified by the cross-tie pretension while ignoring cable sag induced by either gravity or cross-tie pretension. A comparison of the results indicates that the cross-tie pretension affects the system dynamics mainly through modifying cable tension while the introduced change in cable profile only has limited influences on the system lower modes. This study demonstrates the importance of cross-tie pretension in dynamics of cable networks.

中文翻译：

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具有预张紧横梁的双电缆网络的平面内动态行为

用交叉扎带连接电缆以形成电缆网络是抑制电缆振动的可行解决方案。横梁需要预张紧，以防止它们在电缆振动过程中完全松开并受到冲击。然而，现有的大多数研究都忽略了动态分析中的交叉拉杆预应力。因此，本研究调查了交叉系带预紧力对电缆网络平面内动力学的影响。首先研究了对缆索张力和静态剖面的影响。然后执行复模态分析以制定考虑小缆索垂度、横梁刚度和预紧力的缆索网络的特征方程，并详细讨论双缆网络的动力学。发现当横梁未与桥面连接时，由于其预紧力，横梁可以降低系统频率，特别是在由横梁预紧力降低张力的电缆振动占主导地位的模式中。然而，当交叉连接接地时，它似乎总是增加系统频率。此外，基于索的绷紧模型进行了简化分析，考虑了由交叉拉杆预紧力修正的索拉力，同时忽略了由重力或交叉拉杆预紧力引起的索下垂。结果的比较表明，横梁预紧力主要通过改变索张力来影响系统动力学，而引入的索剖面变化对系统低阶模态的影响有限。