摘要
采用希尔伯特-黄变换方法对桥梁原始振动信号进行分析处理,由于原始信号中信噪比不同,导致在经验模态分解过程中出现模态混叠现象,增加了桥梁模态参数识别难度。结合北京立水西桥健康监测系统振动分析实例,通过将带通滤波与希尔伯特-黄变换相结合的方法,提高桥梁振动信号信噪比,消除在经验模态分解过程中的模态混叠现象,并获得信号的时间～频率局部信息,最后通过绘制桥梁振动时间～频率～振幅曲线,识别桥梁阻尼与频率,并将识别成果与荷载试验结果做对比,其误差在合理范围之内。
The Hilbert-Huang Transform method is used to analyze and process the original vibration signals of bridges.As the signal-to-noise ratios in the original vibration signals are different,the modal mixing phenomenon is caused in the process of decomposition of the empirical modals and the difficulty of modal parameter identification for bridges is increased.With reference to the practical examples of vibration analysis implemented by the health monitoring system of the Lishui West Bridge in Beijing and by way of combining the band-pass filter and the Hilbert-Huang Transform,the signal-to-noise ratios of bridge vibration signals are improved,the modal mixing phenomenon in the process of the empirical modal decomposition is eliminated and the local information of time^frequency of the signals is obtained.Further by the plotted time^frequency^vibration amplitude curves,the damping and frequency of bridges are identified and the results of the identification and load testing are compared,of the which the errors are found to be within the reasonable range.
出处
《世界桥梁》
北大核心
2010年第4期54-57,67,共5页
World Bridges
