局部传递率函数与模式匹配的结构损伤快速识别方法

Rapid damage identification of structure based on local transmissibility function and pattern matching

为了对结构进行灾后快速安全评估,提出一种基于局部传递率函数与模式匹配的快速损伤识别方法。通过有限元建立结构不同损伤位置和程度的模型,通过模态分析获取其固有频率与振型,建立损伤模式数据库;根据待测真实结构上少量测点所测振动信号计算局部传递率函数,构建匹配因子矩阵;调用损伤模式数据库中的模态参数构建损伤模式矩阵,建立匹配因子矩阵与损伤模式矩阵间的映射关系;以欧式距离相似度指标来衡量匹配程度,相似度最高的损伤模式即视为待测结构的实际损伤情况。为了验证本方法的可行性和准确性,对一四层层间剪切模型进行数值模拟和实验验证,结果均表明,本方法能够准确识别结构损伤位置和程度。所提方法不涉及复杂的算法,只需少量测点数据,计算速度快,满足震后快速评估要求;该方法只与结构固有属性有关,但无需进行结构模态参数识别,具有良好的实际工程应用前景。

In order to quickly assess the safety of the structure after disaster,a rapid damage identification method based on local transmissibility function and pattern matching is proposed.The finite element models of the structure with different damage scenari⁃os are established.The natural frequencies and mode shapes are obtained through modal analysis and the damage pattern database is established.For the real structure to be assessed,the local transmissibility function is calculated using the vibration signals measured by limited number of sensors installed on the structure to construct the matching factor matrix.Meanwhile,using the modal parame⁃ters stored in the damage pattern database,the damage pattern matrix is also calculated,establishing the mapping relationship be⁃tween the matching factor matrix and the damage pattern matrix.The similarity index obtained by Euclidean distance is used to mea⁃sure the level of the pattern matching.The damage pattern with the highest similarity is regarded as the damage scenario of the real structure,so that the damage is identified.In order to verify the feasibility and accuracy of this method,a four-layer interlayer shear model is simulated and tested in the lab.The results of both simulation and experiment show that the proposed method can accurate⁃ly identify the damage location and severity of the structure.The proposed method has the advantages that it does not involve com⁃plex algorithms,only a small amount of sensors are used,and the calculation speed is fast,which meets the requirements of rapid post-earthquake evaluation of the structure.This method is only related to the inherent properties of the structure,but not requires the structural modal parameter identification.Hence,this method has a good prospect of practical application in engineering.