刚架拱桥病害与损伤识别的动力学研究

从动力学角度研究刚架拱桥典型病害的机理与损伤识别方法,对多座有病害的刚架拱桥进行了振动测试与分析。利用基于环境激励的模态试验技术和振动响应分析获取了刚架拱桥的实际模态参数和主要振动形式。在此基础上通过有限元分析探讨刚架拱桥的动力特性参数和结构损伤之间的关系,提取了对损伤敏感的动力特征参数。研究结果表明:桥面扭转振动是造成桥面裂缝的主要因素之一;桥面一阶扭转振型的频率对横向联系体系的刚度变化非常敏感,可以作为反映结构损伤程度的特征参数。

Damage Identification of Rigid-Frame Arch Bridge Based on Dynamic Tests

To study the mechanism and identification of typical disease of a rigid-frame arch bridge from the point of view of dynamics, a vibrational analysis and testing for several of the bridges were made. The modal parameters and the main vibration patterns were obtained by using ambient experimental technique and response analysis. Based on the analysis and testing results, the relationship between dynamic parameter and structure damage was discussed in detail.Resultes show that the cracks on the deck of the bridge arise mainly from the torsional vibration of the deck and the natural frequency of the torsional vibration of its first mode is quite sensitive to the stiffness of the lateral contact restrain of the bridge, so the frequency can be used as a feature parameter to reflect the degree of damage of the structure.