【作者】 马军海；

【导师】 蔡敏；

【作者基本信息】 合肥工业大学 ， 工程力学， 2004， 硕士

【摘要】 动力测试方法越来越多地被用于斜拉桥的检测分析中，由于动力测试方法的应用，不可避免地涉及到振动测试信号的采集和分析处理问题。 斜拉桥的振动信号常呈现非平稳时变特点，传统的傅里叶分析是一种全局的变换，短时傅里叶变换也存在着当短时窗函数确定后，窗口的形状就确定了的缺陷，不适于处理斜拉桥动测信号。而小波分析方法在低频部分具有较高的频率分辨率和较低的时间分辨率，在高频部分具有较高的时间分辨率和较低的频率分辨率。利用小波分析的多分辨率分析思想，可以聚焦到信号的任意细节进行时频域处理，适合斜拉桥振动状态的监测。 本文在研究将小波分析应用于斜拉桥动测分析时，首先选用恰当的小波基函数，再通过小波分析对信号进行分解和重构消除噪声，并识别在斜拉桥检测含噪信号中有用信号的发展趋势。根据斜拉桥结构在振动时受损部位的振动信号的奇异性，利用小波奇异性检测理论分析斜拉桥结构在受损时的振动信号，判断结构损伤情况。本文通过几个具体的工程实例分析说明了小波应用于斜拉桥动力测试方面的优势。更多还原

【Abstract】 Dynamical detection method is more and more used in detection and analysis of cable-stayed bridge. So it is inevitably involved in gathering and analysis of vibration signal.Vibration signal of cable-stayed bridge often have non-stationary and timely character. Traditional Fourier transform is a kind of whole transformation and short-time Fourier transform have the limitation that if short-time window is ascertained, its shape is also certain. But wavelet analysis method have higher and lower time solution at low frequency, have lower frequency solution and higher time solution. By its multi-solution idea, we can focalize discretionary detail of detection of cable-stayed bridge and process in time field and frequency field. So it is adapt to vibration detection of cable-stayed bridge.The article firstly selects right wavelet group, and decomposes and reconstructs signal by wavelet analysis to delete noise, and distinguishes the development trend of useful signal from detection signal involved in noise of cable-stayed bridge. Based by singularity of vibration signal of damage position on cable-stayed bridge as vibrating, we can analyze vibration signal when cable-stayed bridge is damaged to estimate structure damage. This article illuminates the potential of wavelet application to dynamical detection of cable-stayed bridge.更多还原