基于稳态激励共振试验的人行桥全模态参数识别  

Full modal parameters identification of a footbridge based on a steady-state resonant exciting test

作　　者：温青 周越 宁平华 王晟 华旭刚[3] WEN Qing;ZHOU Yue;NING Pinghua;WANG Sheng;HUA Xugang(Department of Civil Engineering,Hunan University of Science and Technology,411201 Xiangtan,China;Guangzhou Municipal Engineering Design&Research Institute,510062 Guangzhou,China;Key Laboratory for Wind and Bridge Engineering of Hunan Province,Hunan University,410082 Changsha,China)

机构地区：[1]湖南科技大学土木工程学院结构抗风与振动控制湖南省重点实验室,湘潭411201 [2]广州市政工程设计研究院,广州510062 [3]湖南大学风工程与桥梁工程湖南省重点实验室,长沙410028

出　　处：《应用力学学报》2024年第5期1168-1174,共7页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.51708208,51778228,52078210);湖南省教育厅科学研究项目(No.19B194);湖南省自然科学基金项目(No.2021JJ40208,2021JJ10003)。

摘　　要：识别包括模态质量在内的结构真实全模态参数是人行桥人致振动舒适度评价和减振设计的关键工作。提出一种基于稳态激励共振动力试验的人行桥全模态参数识别方法,该方法首先利用稳态激励共振动力试验,得到稳态激振下较大振幅的稳态振动;然后停止激励,从结构自由振动响应中识别结构频率、阻尼比和振型;最后利用稳态振幅以及识别的频率、阻尼比和振型,识别结构的模态质量。该方法仅需要一次激振试验就可以实现包括模态质量在内的人行桥全模态参数识别。通过仿真分析,研究了该方法的可行性以及激振频率偏离对模态参数识别的影响。采用该方法识别了一座大跨人行曲线斜拉桥1阶侧弯模态的全模态参数。研究结果表明,该方法能较可靠识别结构特定模态的频率、阻尼比和模态质量。The full model parameters identification including the modal mass is a necessary issue for comfort assessment and control of human-induced vibration of the footbridges.A method is proposed to identify the full model parameters of the footbridge based on a steady-state resonant exciting test.First,the steady-state vibration with larger amplitude was obtained by a steady-state resonance exciting.Then,after stopping steady-state resonance exciting,the natural frequency,damping ratio and mode shape are identified from the free-decay vibration response of the structure.Finally,the modal mass of the structure was calculated by the tested vibration amplitude and the aforementioned three identified modal parameters.Only one case of dynamic test is needed to be conducted to identify the full modal parameters including the modal mass.The feasibility of the proposed method and the influence of excitation frequency deviation on parameter identification are studied through simulation analysis.The field test of a long-span curve cable-stayed footbridge is preformed to identify the first lateral mode parameters.The results indicated that the method can effectively identify the frequency,damping ratio and modal mass for a certain mode of the footbridge.

关 键 词：人行桥 动力试验 参数识别 模态质量 

分 类 号：O327[理学—一般力学与力学基础]