基于时频分析方法的桥梁结构健康监测系统

摘要

As an important indicator of the status of bridge structure health, bridge vibration signals have the characteristics of non-linear and non-stationary. Time-frequency analysis, an important branch of non-stationary signal processing, makes use of time and frequency joint functions to represent the non-stationary signals, and analyze as well as process them. Vibration signals collected from Hangzhou Xiasha bridge structural health monitoring system are multi-scaled decomposed, de-noised and reconstructed using the wavelet analysis and the HHT method, respectively. Then, comparative studies are taken on these two kinds of time-frequency analysis methods. Experimental results verify the feasibility and effectiveness of the time-frequency analysis on bridge vibration signal dynamic characteristics and provide a theoretical basis for method in the application of a bridge monitoring system.%桥梁的振动信号作为反映桥梁结构健康状况的重要指标,具有非线性、非平稳特点.时烦分析方法是非平稳信号处理的重要分支,该方法利用时间和频率的联合函数来表示非平稳信号,并进行分析和处理.本文针对杭州下沙大桥桥梁结构健康监测系统采集的振动信号,分别利用小波分析和HHT方法进行多尺度分解、去噪与重构,并对两种时频分析方法进行比较研究.实验结果表明了时频分析方法在桥梁振动信号动力特性分析与处理中的可行性与有效性,并为该方法在桥梁监测系统的应用提供了理论依据.