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提出了采用同步挤压小波变换的方法识别移动车辆荷载作用下桥梁时变参数.首先介绍了基于挤压小波变换的时变参数识别理论方法,随后用两层框架结构数值算例验证提出方法的有效性和精度.设计建立了移动小车通过钢梁的试验模型,建立结构的有限元模型并利用模态试验的结果对模型进行校正.采集车辆通过主梁时的加速度响应和应变响应,由应变数据估计小车不同时刻在梁上的位置,对加速度响应数据采用提出的方法识别结构的瞬时频率,与有限元计算的结果进行对比分析.研究结果表明:提出的方法能有效准确地识别时变结构的瞬时频率,具有一定的抗噪性.
A time-varying parameter identification method based on squeezed wavelet transform is proposed firstly by using the method of synchronous squeeze wavelet transform to identify the time-varying parameters of bridge under moving vehicle loads. Then, the numerical example of two-layer frame structure is used to verify the proposed method The validity and the precision of the model.A test model of the mobile trolley passing through the steel beam is designed and established.The finite element model of the structure is established and the model is calibrated by using the modal test results.The acceleration and strain responses of the vehicle passing through the main girder are collected, Data are used to estimate the position of the trolley on the beam at different time points, and the instantaneous frequency of the structure is identified by the proposed method for acceleration response data, which is compared with the results of the finite element analysis. The results show that the proposed method can effectively and accurately identify the time-varying structure The instantaneous frequency, with a certain degree of anti-noise.