针对混凝土材料中所产生的声发射(AE)信号复杂的特点,采用正交异性声发射传感器(OAET)提取结构中特定方向的AE信号。运用Hilbert—Huang变换(HHT)对AE信号进行分析,通过循环应用经验模态分解的方法,将复杂的原始数据序列分解为有限数目的固有模态函数及一个残余项,进而采用Hilbert变换,得到以时间为自变量的信号幅度和瞬时频率函数。文章探讨了基于幅度和瞬时频率函数的损伤识别方法,形成了一种混凝土中复杂AE信号处理及损伤识别的新途径,有助于AE技术的发展与推广应用。
The sensor of Orthotropic Acoustic Emission Wave Transducer is used to obtain the directional AE signal in order to deal with the complicated AE signal produced in concrete. Hilbert-Huang transform is applied in the signal processing. The complicated original data set is decomposed into a finite series of intrinsic mode function (IMF) and a residue by the empirical mode decomposition (EMD). The signal amplitudes and instantaneous frequency as function of time can be gained byusing Hilbert transform to the IMF components. The damage identification method based on amplitudes and instantaneous frequency is discussed, and a new method for concrete AE signal processing and damage identification is proposed. It will be helpful for the development, popularization and application of AE signal.