摘要
斜拉索是斜拉桥的重要受力构件,当索梁耦合振动时,斜拉索易发生大幅的参数振动。本文提出了一个不计拉索垂度并忽略桥梁自重影响的单自由度力学模型,推出了斜拉索参数振动的简化分析方程。为了考察方程的可行性,利用计算机对该方程进行了仿真,并与另一考虑索桥耦合作用运动方程的仿真分析作了对照,得到了非常相近的结果。基于实验室24.2m的模型斜拉索,辨识了该拉索的固有频率和阻尼,通过试验实现了该斜拉索的一阶参数振动,并分析了发生一阶参数振动时激励频率与固有频率比值。另外运用本文提出的简化方程对实验室拉索作了仿真,得到了参数振动现象,与实验结果对比得到:利用简化分析模型对试验拉索的仿真分析与实验室拉索的实验结果比较吻合,表明不考虑桥梁质量的简化模型具有足够的准确性。最后,结合工程实例,对鄂东大桥的某一可能发生参数振动的拉索进行了仿真分析,表明在桥梁自重较重时本文所提出的简化方程具有较好的适用性;并且发现加装阻尼器可以有效抑制拉索的参数振动。
The stayed cable is an important force member of the cable-stayed bridge.When the beam is coupled with vibration,the cable inclines to having a large parametric vibration.This paper proposes a mechanical model with single-degree-of-freedom in which the bridge weight is neglected,a simplified analytical equation of parametric vibration of stayed cables is built up.In order to investigate the feasibility of the equation,the equation is simulated and compared with another simulation analysis considering the coupled equations of motion of the cable-stayed bridge.The results are very similar.Based on the 24.2 m model diagonal cable in laboratory,the natural frequency and damping of the cable are identified.The first-order parametric vibration of the cable is tested and the ratio between excitation frequency and intrinsic frequency is recognized.In addition,the simplified model presented in this paper was used to simulate the cable in the laboratory.The parametric vibration is obtained.Compared with the experimental results obtained,the simulation analysis of the lab cable using the simplified analysis model is in good agreement with the experimental results of the lab cable,indicating that the simplified model without consideration of the bridge mass has sufficient accuracy.Finally,combining with the engineering example,a certain cable vibration of the E Dong Bridge is simulated.Moreover,it is found that adding dampers has better restraining effects on the parametric vibration of cables.
作者
方豪杰
王修勇
罗一帆
孙洪鑫
彭剑
Fang Haojie;Wang Xiuyong;Luo Yifan;Sun Hongxin;Peng Jian(Hunan Provincial Key Laboratory of Structures for Wind Resistance and Vibration Control,College of Civil Engineering,Hunan University of Science and Technology,411201,Xiangtan,China)
出处
《应用力学学报》
CAS
CSCD
北大核心
2019年第2期438-443,513-514,共7页
Chinese Journal of Applied Mechanics
基金
国家重点基础研究发展计划(973计划)(2015CB057702)
国家自然科学基金(51378203)
湖南省研究生科研创新项目(CX2017B627)
关键词
桥梁工程
斜拉索
参数振动
有限元
仿真分析
实验
bridge engineering
diagonal cable
parametric vibration
finite element method
simulation analysis
experiment
