基于运营环境和提升小波变换的桥梁损伤检测研究

Research on Bridge Damage Detection Based on Operational Environment and Lifting Wavelet Transform

根据损伤桥梁在车辆荷载作用下的动力响应特点,以及提升小波变换对信号突变信息的放大功能,提出了利用桥梁运营荷载作用下加速度响应提升小波变换系数的分布特性对结构损伤进行识别的方法。首先,采集桥梁在行车荷载作用下的加速度响应信号;然后,对加速度响应信号进行提升小波变换,分别利用加速度响应信号、加速度响应信号差,提升小波变换系数空间变化的峰值识别损伤位置;最后,对行车速度、损伤位置、损伤程度和测量噪声对损伤识别效果的影响进行了分析讨论。结果表明:在行车速度8m/s以下、测量噪声不高于5%情况下,利用运营荷载作用下桥梁单点动力响应信号提升小波变换,可以实现桥梁多处损伤的检测和识别。

According to the dynamic response characteristics of damaged bridges under vehicles load,and magnifying function of lifting wavelet transform at signal break point,the structural damage identification method has been proposed by the distribution characteristics of lifting wavelet transform coefficient of acceleration response of bridge under a moving load.Firstly,the acceleration response signal of the bridge subjected to a moving load is captured.Then the signal is transformed by lifting wavelet.The damage location is determined by spatial variation of lifting wavelet transform coefficients of acceleration response and acceleration response difference respectively.At the same time,the damage identification effect has been analyzed and discussed under the different speed of vehicle,the different damage location,the different damage severity and noise level.The following study results show that when the speed of vehicle is less than 8m/s and the noise level is less than 5%,the multiple site damage may been detected and determined by the lifting wavelet coefficients of a dynamic response signal of bridge under vehicles load.