Application of HHT for modal parameter identification to civil structures

结合青马桥的实测动力响应记录,研究HHT方法在结构模态参数识别中的应用。为讨论HHT方法处理非平稳数据的性能,将HHT方法分别用于平稳及非平稳的实测记录以识别结构的频率和阻尼,并与有限元分析及谱分析结果进行比较。对比表明HHT方法有很好的识别效果,在处理非平稳性数据方面具有明显优势,适用于土木工程结构的模态参数识别。||The practical application of HHT method for modal parameter identification to civil structures is investigated in this paperi with emphasis on its ability for handling non-stationary measurement data. To this end, the acceleration response time histories of TsingMa Bridge during strong Typhoon Victor are analysed. Two 10-min long time-histories, one is stationary and the other non-stationary, are extracted from the measured records. From them the natural frequencies and modal damping ratios of the bridge are identified using HHT method in combination with random decrement technique. The identification results are compared with those provided by finite element analysis and the Fast Fourier Transform (FFT) method in conjunction with the bandwidth method. The results demonstrate that the HHT method is effective, robust and promising to structural parameter identification for large civil structures.