环境激励下基于波动能量法的结构损伤识别

Identification of structural damage based on wave energy method under ambient excitation

目前作为结构健康监测系统核心的损伤识别大多是基于模态参数变化而进行的,但模态参数对局部损坏不敏感,导致损伤识别精度不够。波在结构中的传播状态可以更好地反映局部损伤状况,波动能量可以作为损伤识别的有效指标。为了提高环境激励下结构损伤识别的精度,采用S变换分析了结构输出信号,建立波动能量指标,从而使波动能量指标的使用领域扩展到非平稳信号范围。最后通过三层钢框架试验及弹性分层剪切梁的数值模型对该方法进行了验证,结果表明:该方法不仅能够有效识别结构损伤位置,而且能够识别出损伤程度。

At present,the damage identification as the core of the structural health monitoring system is mostly based on modal parameter changes,but the modal parameters are not sensitive to local damage,resulting in insufficient damage identification accuracy.The wave propagation state in the structure can better reflect the local damage status,and the wave energy can be used as an effective indicator for damage identification.In order to improve the accuracy of structural damage recognition under environmental excitation,S transform is used to analyze the output signal of the structure and establish the wave energy index,so that the application field of the fluctuation energy index is extended to the range of non-stationary signals.Finally,the method is verified by the three-story steel frame test and the numerical model of elastic layered shear beam.The results show that the method can not only effectively identify the location of structural damage,but also the degree of damage.