行人荷载作用下钢木组合人行桥结构时变频率识别及变化规律研究  

Study on Time-varying Frequency Identification and Its Variable Rule of Steel-timber Composite Footbridge Excited by Pedestrian Load

作　　者：彭佳敏 刘景良 陈飞宇[1] 郑文婷 盛叶 骆勇鹏 PENG Jiamin;LIU Jingliang;CHEN Feiyu;ZHENG Wenting;SHENG Ye;LUO Yongpeng(School of Transportation and Civil Engineering,Fujian Agriculture and Forestry University,Fuzhou 350108,China;“Digital Fujian”Laboratory of Internet Things for Intelligent Transportation Technology,Fujian Agriculture and Forestry University,Fuzhou 350108,China;School of Civil Engineering,Fujian University of Technology,Fuzhou 350118,China)

机构地区：[1]福建农林大学交通与土木工程学院,福州350108 [2]福建农林大学“数字福建”智能交通技术物联网实验室,福州350108 [3]福建工程学院土木工程学院,福州350118

出　　处：《噪声与振动控制》2022年第6期203-211,266,共10页Noise and Vibration Control

基　　金：国家自然科学基金青年基金资助项目(51608122);福建省自然科学基金面上资助项目(2020J01581,2020J01579);福建农林大学科技创新专项基金资助项目(CXZX2020112A);福建省林业科技资助项目(闽林科(2020)29号)。

摘　　要：钢-木组合结构因其良好的承载能力与环境协调性目前多用于人行桥等结构系统。为追踪行人与钢木组合人行桥耦合作用所导致的频率变化特性,建立人体与钢木组合人行桥耦合的数值模型并求解其振动响应。由于人致振动产生的响应信号有可能是非渐近和密集的,采用一种拓展解析模态分解、递归希尔伯特变换和变焦同步挤压小波变换相结合的联合方法识别其时变模态特性。研究结果表明:该模型能够很好地模拟人或人群与钢木组合人行桥之间的相互作用;在单人或是人群作用下该联合方法均能准确识别出耦合系统的频率变化并具有一定的鲁棒性。在此基础上,对不同跨径钢木组合人行桥进行数值模拟并分析不同人体参数对人-桥耦合系统固有频率的影响,最终得到人-钢木组合桥耦合系统频率随行人荷载的变化规律并拟合出经验公式。该公式能够为人行桥的设计、维护等提供参考。The steel-timber composite(STC) structure is frequently used for footbridges due to its good bearing capacity and environmental harmony.In order to trace the feature of frequency change caused by the interaction between pedestrian and STC footbridge,a finite element model for analyzing pedestrian-STC footbridge interaction is established and its pedestrian-induced vibration response is calculated.Since the resultant response signal is possibly non-asymptotic and has a modal-overlap,a combined method which unites the extended analytical mode decomposition,recursive Hilbert transform and zoom synchro-squeezing wavelet transform is used for time-varying modal characteristics identification.The results demonstrate that the proposed model is capable for simulating the interaction between the pedestrian and STC footbridge well.In addition,the combined method can accurately indicate the frequency change of the interaction system with robustness under the excitations of single person and crowd,respectively.To investigate the impact of human parameters on the natural frequency of the human-STC footbridge interaction system,extensive simulations on STC footbridges with different spans are carried out.On this basis,the relationship between the instantaneous frequency of human-STC footbridge interaction system and the pedestrian movement is obtained and thus an empirical equation is proposed by curve fitting.This empirical equation has the potential to provide a guideline for the pedestrian bridges design,maintenance etc.

关 键 词：振动与波 钢木组合结构 人桥相互作用 同步挤压小波变换 时变 联合方法 瞬时频率 

分 类 号：TN911.6[电子电信—通信与信息系统] TU311.3[电子电信—信息与通信工程]