桥梁固有模态的识别

Modal Identification of Bridges

介绍了所编制的实桥环境随机振动测试数据处理及固有模态识别程序ＥＤＰＦＤＭ．该程序以频域法为基础，可对经实桥分组环境随机振动测试而得的大量数据进行快速自谱、互谱及相位差和凝聚性分析，从而识别出桥梁的固有模态及对应的结构阻尼比的估计范围．以香港汲水门大桥固有模态环境随机振动测试为实例，结合用ＭＳＣ－ＮＡＳＴＲＡＮ通用程序的模态分析结果。

A program, EDPFDM, for the identification of bridge's eigen modalities using ambient vibration method, is presented based on the frequency domain method in this paper. It can analyse the spectra of the ambient vibration signals, which are recorded at measurement points on a bridge, at a tremendous speed, and discern out the eigen modalities of the bridge. Finally, the reliability and effectiveness of EDPFDM is confirmed after the data reduction of the recorded ambient vibration signals of Kap Shui Mun Bridge. The identified dynamic parameters of the bridge are very close to those computed by the program of MSC-NASTRAN.