钢筋混凝土构件损伤状态的声发射识别

Damage Identification in Reinforced Concrete Components Using Acoustic Emission

为实现钢筋混凝土构件的损伤识别,利用声发射技术对钢筋混凝土梁进行了损伤监测研究。采用Hilbert-Huang变换对声发射信号进行了分析,利用经验模态分解(EMD)将信号分解为固有模态函数(IMF),得到Hilbert谱,反映信号时频特性。从IMF中提取声发射特征参数,即固有模态函数最大瞬时幅值和特征瞬时频率。通过参数与波形的混合分析,确定钢筋混凝土构件的损伤状态,获得结构加固修复和失效破坏的两个安全预警信号,为声发射技术应用于钢筋混凝土结构健康监测提供理论基础。

To realize the damage identification using acoustic emission （AE） technique, experimental study on damage detection in reinforced concrete beams was performed. The Hilbert - Huang transform （ HHT） was employed to analyze AE signals. By using empirical mode decomposition （EMD） , the AE signals were decom- posed to several intrinsic mode functions （IMF） , and Hilbert spectrums were derived. The maximum instanta- neous amplitude of IMF and the characteristic instantaneous frequency were extracted from the IMFs. The dam- age conditions of reinforced concrete components were identified by a hybrid method with AE parameters and waveforms. Two early warning signals for structural strengthening and retrofitting, and destruction were also ob- tained. The results provided theoretical bases for AE application in the health monitoring of reinforced concrete structures.