基于HHT-RDT算法的高拱坝泄流结构工作模态识别方法

根据高拱坝泄流结构自身的工作特点,为准确辨识环境激励下的结构模态参数特征,提出了一种基于改进的HHT-RDT算法的高拱坝泄流结构工作模态识别方法。以某高拱坝原型振动响应测试资料为基础,利用改进的小波阈值-EMD算法对原始信号进行降噪预处理,滤除干扰噪声的同时保留有效特征信息;采用HHT-RDT算法识别高拱坝泄流结构的工作模态参数,运用带通滤波对振动响应信号的EMD过程进行控制得到结构的各阶模态分量,利用RDT法提取各阶模态分量的自由衰减信息,识别出高拱坝泄流结构系统的固有频率及阻尼比。工程实例表明,该方法避免了复杂系统定阶过程,有效提高结构振动响应工作模态识别精度,为辨识高拱坝泄流结构的工作模态参数提供捷径。

Working modal identification method for high arch dam discharge structure based on HHT-RDT algorithm

According to the working characteristics of high arch dam discharge structure,a working modal identification method of high arch dam discharge structure based on improved HHT-RDT algorithm was proposed to accurately identify the structural modal parameters under environmental excitation. Based on the prototype vibration response of high arch dam, the improved wavelet threshold-EMD algorithm was used to filter out interference noise while retaining valid characteristic information. The working modal parameters of the discharge structure of the high arch dam were identified by the HHT-RDT algorithm: the EMD process of the vibration response signal was controlled by band-pass filtering to obtain the modal components of the structure, and the natural frequency and damping ratio of the discharge structure system of the high arch dam were identified. The engineering example shows that the proposed method can avoid the complex ordering process of the system, improve the accuracy of working modal identification, and make it easier for the working modal parameter identification of high arch dam discharge structure.