加速度功率谱密度在钢桥损伤检测中的应用

Damage Detection of Steel Bridge Based on Acceleration Power Spectral Density

利用振动特性变化对结构进行无损检测,是近期损伤检测领域的热门研究课题。振动特性能够反映结构的状态,损伤的产生会导致桥梁某些振动参数的变化。为了研究应用加速度反应功率谱密度这一振动特性进行钢桥损伤识别方法,本文采用废止铁路线钢桥为试件,并人工预置6种工况损伤。利用正弦扫频波激振钢桥,分析其损伤前后加速度反应功率谱密度的变化。实验结果表明,利用加速度反应功率谱密度变化能够准确识别并定位钢桥损伤的位置。

Non-destructive testing of structure with the change of vibration characteristics attracted much attention in recent years. The basic idea of this method is that the vibration characteristics can reflect the state of the structure, and damages can cause changes of bridge vibration parameters. In order to study the method detecting steel bridge damages based on the power spectral density （PSD） of acceleration response, a disused railroad bridge in Japan was adopted as specimen, and six cases of damage were introduced to it in advance. The bridge was actuated by sinusoid sweeping frequency wave, and then the power spectral density differences between the undamaged and damaged bridge were analyzed. Experimental results show that the steel bridge damages can be detected and located by the changes of acceleration PSD.