结构损伤识别的小波包分析试验研究

在结构服役期内，由于局部损伤的累积发展将导致结构刚度等特性的降低，可能导致灾难性的事故。传统的基于模态参数的损伤识别方法有时效果并不理想。提出基于小波包变换的能量变化率指标，并用其进行损伤识别的方法。首先将所得的结构响应信号进行小波包分解，然后通过小波包能量变化率指标进行损伤定他。通过三种不同损伤工况的梁体室内试验，证明所提出的损伤指标可以准确地识别损伤位置。

DAMAGE DETECTION AND IDENTIFICATION OF STRUCTURES IN LABORATORY BASED ON WAVELET PACKET ANALYSIS

During the service of structures,local damage at their key positions will continually accumulate,and(finally) lead to sudden increase of structure damage.This will result in outburst decrease of local stiffness and reduction of structure trait.Traditional modal properties are poor indications of damage.In this study,a damage detection index,namely,wavelet packet energy rate index,is proposed for the damage detection of structures.Dynamic signals measured from experiment beams are first decomposed into wavelet packet components,then wavelet energy rate index is computed and used to detect location of damage.The three kinds of damage locations of beams in laboratory are designed to prove the validity of energy index in experiment.The results show that the WPT-based energy rate index is good candidate index that is sensitive to structural damage.