华南理工大学学报(自然科学版) ›› 2023, Vol. 51 ›› Issue (7): 61-71.doi: 10.12141/j.issn.1000-565X.220631

所属专题: 2023年土木建筑工程

• 土木建筑工程 • 上一篇    下一篇

索网-阻尼器系统自振特性研究

甄晓霞1 刘桂源1 董春光2 张卓杰3 李明阳4   

  1. 1.华南理工大学 土木与交通学院,广东 广州 510640
    2.保利长大工程有限公司,广东 广州 510075
    3.石家庄铁道大学 省部共建交通工程结构力学行为与系统安全国家重点实验室,河北 石家庄 050043
    4.佛山市交通科技有限公司,广东 佛山 528000
  • 收稿日期:2022-09-29 出版日期:2023-07-25 发布日期:2023-01-17
  • 通信作者: 张卓杰(1986-),男,博士,副教授,主要从事大跨度桥梁结构理论研究。 E-mail:stdzhangzhuojie@163.com
  • 作者简介:甄晓霞(1976-),女,博士,副教授,主要从事大跨度桥梁结构动力特性及病害诊断研究。E-mail:xxzhen@scut.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(52178138);广东省自然科学基金资助项目(2021A1515012064)

Study on Natural Vibration Characteristics of Cable Network-Damper System

ZHEN Xiaoxia1 LIU Guiyuan1 DONG Chunguang2 ZHANG Zhuojie3 LI Mingyang4   

  1. 1.School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510640,Guangdong,China
    2.Poly Changda Engineering Co. Ltd. ,Guangzhou 510075,Guangdong,China
    3.State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,Hebei,China
    4.Foshan Transportation Science and Technology Co. Ltd. ,Foshan 528000,Guangdong,China
  • Received:2022-09-29 Online:2023-07-25 Published:2023-01-17
  • Contact: 张卓杰(1986-),男,博士,副教授,主要从事大跨度桥梁结构理论研究。 E-mail:stdzhangzhuojie@163.com
  • About author:甄晓霞(1976-),女,博士,副教授,主要从事大跨度桥梁结构动力特性及病害诊断研究。E-mail:xxzhen@scut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(52178138);the Natural Science Foundation of Guangdong Province(2021A1515012064)

摘要:

斜拉桥中多根斜拉索与辅助索、阻尼器连接形成多层索网-阻尼器系统,可有效实现斜拉索减振。为深入了解该系统的真实动力行为,揭示辅助索、阻尼器作用的相互影响规律,文中提出了多层索网-阻尼器系统模型,将辅助索简化为线性弹簧单元,通过理论推导得到系统的复特征方程,进而求解出系统各阶自振频率、阻尼比,并提出了局部振动模态参数以表征系统不同模态的局部振动程度及系统中的能量分布规律,辅助判断系统振动的整体性;借助实验及有限元仿真分析方法验证了理论公式的正确性;研究了辅助索从柔到刚变化过程中三层索网-单阻尼器系统振型、频率、局部振动模态参数及阻尼比的变化规律,分析了辅助索刚度、阻尼器位置变化对系统阻尼比的影响。研究结果表明:多层索网-阻尼器系统的形成具有减小拉索振幅、提高系统阻尼比的效果;辅助索刚度变化和设置索端阻尼器都会使系统的多阶振型发生相应的变化,阻尼器索端锚固位置变化也会引起个别阶振型的变化,阻尼比与阻尼器所在索段振型振幅密切相关,与辅助索刚度变化密切相关;并非所有模态阻尼比都会从索端阻尼器的设置中获益。总体来说,阻尼器在索端锚固点距离桥面越远,对阻尼器发挥作用愈有利;辅助索刚度越大,系统的整体性越好,频率越高,各拉索之间的相互约束更强。

关键词: 索网-阻尼器系统, 振动控制, 阻尼比, 局部振动特性

Abstract:

In cable-stayed bridges, multiple stay cables are connected with cross-ties and dampers to form a multilevel cable network-damper system, which can effectively reduce the vibration of stay cables. In order to deeply understand the real dynamic behavior of the system and grasp the interaction law of cross-ties and dampers, this paper proposes a model of multilevel cable network-damper system, which simplifies the cross-ties into linear spring elements, and obtains the complex characteristic equation of the system through theoretical derivation. Next, the natural frequency and damping ratio of each order of the system are solved, and local mode parameter is proposed to characterize the local vibration degree of different modes as well as the energy distribution rules of the system, and, furthermore, auxiliary estimate the vibration consistent of the system. Then, the proposed theoretical formulation is verified by the experiment and finite element simulation. Fnially, the changes of vibration mode, frequency, local mode parameter and damping ratio of the triple-layer cable network-single damper system during the change of cross-ties from flexible to rigid are investigated, and the effects of the cross-tie stiffness and damper position on the damping ratio of the system are analyzed. The results show that the multilevel cable networks-damper system decreases the amplitude of the cables and increases damping ratio of the system; that the stiffness change of the cross-tie and the set of damper at the cable end may both lead to corresponding change of multi-order system mode shape; that the change of anchoring position of the damper at the cable end may also cause individual mode shape change.; that the damping ratio is closely related to the amplitude of the section where the damper is located and to the stiffness change of the cross-tie; and that not all mode damping ratios benefit from the damper set at the cable end. In general, the farther the damper is from the bridge deck at the cable-end anchor point, the more favorable it is for the damper to play; the greater the stiffness of the auxiliary cable, the better the integrity of the vibration system; the higher the frequency, the stronger the mutual constraint between the cables.

Key words: cable network-damper system, vibration control, damping ratio, local vibration characteristics

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