基于测量位移和频率的结构损伤二次识别方法

为了解决结构多损伤下的位置识别和损伤程度的判定问题，将测量位移和频率用于结构的损伤检测研究，并提出了一种分阶段的二次损伤识别方法。首先考虑测量位移数据量多且包含信息量较大的特点，利用测量的位移数据进行损伤的初次定位识别；然后利用频率的测量精度较高的优势，采用频变法进行结构损伤的定量识别。并针对频变法提出了相应的迭代改进策略，以进一步提高损伤识别的精度。数值仿真结果表明，采用测量位移定位识别可以有效地获得可能的损伤单元，在此基础上利用频变法的迭代改进策略不仅可以得到损伤程度的量化值，而且可以更精确的判断损伤的位置。

TWO-STAGE STRUCTURAL DAMAGE IDENTIFICATION METHOD BASED ON MEASURED DISPLACEMNTS AND FREQUENCIES

In order to identify structural multi-damage locations and levels,a two-stage damage detection method is presented by using measured displacements and frequencies.Considering the feature that the data and information of measured displacements are often much more than those of measured natural frequencies,we firstly utilize the measured displacements to localize the damage sites.Then the frequency change method is used to calculate damage levels because the frequencies can be measured with better accuracy.And an iteration algorithm for improvement of the frequency change method is proposed,which can increase the identification precision.The simulation results demonstrate that the proposed two-stage method can perfectly detect structural damage and the iteration improvement strategy is obviously better than the frequency change method.