\r熊春宝¹，于丽娜¹，常翔宇\r²\r
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AuthorsHTML:\r熊春宝¹，于丽娜¹，常翔宇\r²\r
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AuthorsListE:\rXiong Chunbao¹，Yu Lina ¹，Chang Xiangyu\r²\r
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AuthorsHTMLE:\rXiong Chunbao¹，Yu Lina ¹，Chang Xiangyu\r²\r
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Unit:\r\r1. 天津大学建筑工程学院，天津300072；\r
\r\r2. 天津市交通科学研究院，天津 300074\r
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Unit_EngLish:\r1. School of Civil Engineering，Tianjin University，Tianjin 300072，China；
2. Tianjin Transportation Research Institute，Tianjin 300074，China\r
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Abstract_Chinese:\r\r为研究环境激励下大跨径桥梁结构振动响应特性，采用拾振器监测结构动态变形．针对监测信号中的噪声影响，提出\rEEMD\r-\r小波阈值联合滤波方法来提升信号精度．首先，利用\rEEMD\r算法对信号进行分解，基于平均周期图法和相关系数法双重判定准则剔除虚假分量，然后，结合小波阈值去噪方法对重构信号进行二次降噪，再利用\rRDT\r-\rITD\r法识别结构模态参数．将滤波降噪和模态识别方法应用于天津永和桥实测振动响应分析中，并结合有限元分析结果进行对比．结果表明：\rEEMD\r-\r小波阈值联合滤波方法优于应用单一方法，能进一步提升信号精度；信号降噪后，利用\rRDT\r-\rITD\r方法成功提取了结构前\r3\r阶竖向自振频率和相应阻尼比；识别的结构自振频率值与有限元分析结果基本一致，基频值相差\r3.07\r%\r．\r\r
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Abstract_English:\r\rTo investigate the vibration response characteristics of long-span cable-stayed bridge structures under environmental excitation\r，\rpickup sensors are used to monitor the dynamic deformation of the structures\r．\rGiven the presence of noise in the monitoring signal\r，\rthe filtering method of ensemble empirical mode decomposition \r(\rEEMD\r)\rcombined with wavelet threshold denoising is proposed to improve the signal accuracy\r．\rFirst\r，\rEEMD is used to decompose the monitoring signal\r．\rOn the basis of the double criteria of the mean periodic diagram and correlation coefficient methods\r，\rthe false components are removed and the remaining IMF components are reconstructed\r．\rThen\r，\rthe wavelet threshold denoising method is used to conduct secondary noise reduction of the reconstructed signal\r．\rFinally\r，\rthe RDT-ITD method is used to identify the structural modal parameters\r．\rThis combined method is applied to process the vibration response of Tianjin Yonghe Bridge\r，\rand the finite element model of the structure is built for comparison\r．\rThe field measurement and finite element simulation results show that the combined filtering method of EEMD and wavelet threshold denoising is better than a single method and can further improve the signal accuracy\r．\rThe first three vertical natural frequencies and the corresponding damping ratios of the structure are extracted successfully\r．\rThe natural frequency results obtained from field measurement are consistent with the finite element simulation results\r．\rMoreover\r，\rthe difference of the natural frequency for the first order is 3.07\r%\r，\rwhich verifies the validity of the combined method\r．\r\r
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Keyword_Chinese:大跨斜拉桥；EEMD；小波阈值去噪；有限元模拟；模态参数识别\r

Keywords_English:long-span cable-stayed bridge；ensemble empirical mode decomposition(EEMD)；wavelet threshold denoising；finite element simulation；modal parameter identification\r


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