基于缩尺斜拉桥模型的结构损伤分析试验研究

Experimental Study on Structural Damage Identification Based on a Scale Cable-Stayed Bridge Model

摘要: 微小的结构损伤可能引起大型工程结构的破坏性失效和灾难性事故，为解决该类损伤识别问题，需要寻找有效的损伤识别参数。基于某缩尺斜拉桥模型的加速度数据，本文研究了模态频率、模态确认准则、以及模态坐标置信因子三种基于结构振动模态的损伤识别方法。首先在MATLAB中建立了结构的有限元模型，进行了损伤识别参数的敏感性分析；然后在缩尺模型上进行了振动试验，比较验证了三种损伤识别方法的效果。研究表明，三种方法能够识别出结构较为明显的损伤，但是对微小的损伤不敏感。

Abstract: Small damage of a component would probably cause the failure of the whole structure and even induces a disaster. In order to identify this type of damage, effective damage indices were required. Based on the acceleration data of a scale cable-stayed bridge model, three damage identification methods based on structural vibration modes, namely modal frequency, modal confirmation cri-terion (MAC) and modal coordinate confidence factor (COMAC), are studied in this paper. Firstly, the finite element model of the structure is established in MATLAB, and the sensitivity analysis of damage identification parameters is carried out. Then vibration tests are carried out on a scale model to verify the effectiveness of the three damage identification methods. The research shows that the employed methods manage to identify the obvious damage of the structure, but they are insensitive to minor damage.