斜拉桥损伤识别的模态柔度指标分析

结合斜拉桥结构，应用高精度三维有限元模型，对桥面损伤位置识别的模态柔度指标进行了研究。探讨了柔度指标的构造、模态参数的选取及其对计算精度的影响和对斜拉桥可能损伤情况的灵敏性与稳定性等。用于损伤识别的模态柔度指标在构造上可以克服实际应用上的不完全测量所带来的困难，对测点位置和数量均不做过强的约束。柔度指标的构造方式体现了振型与频率的综合特性，具有较好的灵敏性和稳定性。通过少量低阶模态参数就能够计算得到可靠的柔度指标，因此，为实际测量带来较大方便。

Analysis of Modal Flexibility Index for Locating Damage in Cable-stayed Bridges

Based on a precise and validated three-dimensional finite element model, the modal flexibility index for damage localization in the cable-stayed bridges is investigated. This study includes the construction of the index, selection of modal parameters for calc~ating the index, the influence of the parameters on the index accuracy, and sensitivity and stability of the index to the possible damage cases in cable-stayed bridges. The analysis shows that modal flexibility index is helpful to overcome the difficulties arising from incomplete measurement, the index has no particular restriction to the location and number of the measurement points, the index can be obtained with high accuracy by a few of modals, the index shows higher sensitivity and stability for its integration of mode shape and frequency.