In‐plane dynamic behaviors of two‐cable networks with a pretensioned cross‐tie
In‐plane dynamic behaviors of two‐cable networks with a pretensioned cross‐tie
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DOI：
10.1002/stc.2755
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发表时间：
2021-04
影响因子：
5.4
通讯作者：
Fangdian Di;Limin Sun;Lin Chen
中科院分区：
文献类型：
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作者：
Fangdian Di;Limin Sun;Lin Chen
用枕木连接电缆形成电缆网络是抑制电缆振动的可行解决方案。交叉拉杆需要预张紧，以防止它们完全释放，并在电缆振动期间受到冲击。然而，大多数现有的研究都忽略了动力分析的交叉拉杆预张力。因此，本研究探讨了交叉拉杆预张力对索网面内动力学的影响。首先研究了斜拉索张力和静力剖面的影响。然后进行复模态分析，建立了考虑小索垂度、系杆刚度和预张力的索网特征方程，并详细讨论了双索网的动力学特性。研究发现，当系杆未连接到桥面时，由于其预张力，系杆可能会降低系统频率，特别是在张力因系杆预张力而降低的拉索振动占主导地位的模式下。然而，当交叉连接到地面时，它似乎总是增加系统频率。此外，基于拉索的张弦模型进行了简化分析，考虑了拉索张拉力由拉杆预张力修正，而忽略了由重力或拉杆预张力引起的拉索垂度。结果表明，交叉拉杆预张力主要通过改变拉索张力来影响系统动力学特性，而引入的拉索线形变化对系统低阶模态的影响有限。这项研究证明了交叉拉杆预张力在索网络动力学中的重要性。
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.