改进曲率模态识别桥梁损伤位置方法研究

Bridge damage location identification by improved curvature mode

结构健康监测和结构状态评估的主要前提之一是结构损伤识别。基于曲率模态对结构局部损伤比较敏感和频率指标测试简单方便、精度高的特点,本文提出了一种以结构的曲率模态为基础,综合考虑频率的变化的改进的结构损伤识别方法。随机子空间方法是一种行之有效的基于环境激励的结构状态识别方法。该方法的主要优点是无需人工激励,不中断桥梁的运营。为此,论文提出了一种不中断桥梁运营的基于改进曲率模态的桥梁结构损伤识别方法。最后用一三跨连续梁的有限元模型对该改进方法进行了验证。结果表明,采用随机子空间结合改进的曲率模态方法可以在不中断桥梁运营的前提下有效地识别出桥梁的损伤状况。

Structural damage identification is one of the major premises of structural health monitoring and structural condition assessment.Because the curvature mode is sensitive to structural damage location and the frequency is easy to test and precise,this paper presents a curvature mode based improved structural damage identification method.Stochastic subspace method is an effective structural condition identification method,which is based on the ambient excitation.The main advantage of the stochastic subspace identification method is that the artificial excitation is not needed,and it does not interrupt the operation of the bridge.Finally,the method is evaluated by numerical simulation in a three-span continuous beam.The results show that the improved method combined with stochastic subspace identification and improved curvature mode is an effective method to identify the bridge damage condition under the ambient excitation without interrupting the operation of the bridge.