基于经验小波变换的复合材料板声发射源定位

声发射（AE）技术是一种无损检测方法，可以对飞行器中复合材料结构的动态缺陷进行监测。针对AE信号模态成分复杂以及复合材料各向异性导致源定位精度不高的问题，提出基于经验小波变换（EWT）的广义互相关（GCC）时差定位（TDOA）算法。通过EWT对传感器观测到的AE信号进行自适应的分解重构得到其主频模态，有效提高了各通道信号间的相关系数；通过多向波速测量实验对波速进行了多项式拟合；采用GCC法求取各通道信号的时差对AE源进行定位。在平台实验中以T800型碳纤维复合材料板为对象，以断铅信号为AE源对算法进行了验证，实验结果证明了算法的准确性和实用性。

Acoustic emission source location for composite plate based on empirical wavelet transform

Acoustic emission (AE) technique is a non-destructive damage test method. It can be used to monitor the dynamic defects of composite structures in aircraft. The complex components of AE signal and the anisotropy of composite materials lead to the low positioning accuracy of the source. A method of time difference of arrival (TDOA) based on empirical wavelet transform (EWT) and generalized cross-correlation (GCC) is proposed to improve the location accuracy of AE source. EWT is used to adaptively decompose and reconstruct the AE signals observed by sensors. The dominant frequency modes are obtained and the correlation coefficients between signals in each channel are effectively increased. The wave velocity is polynomial fitted by the multidirectional wave velocity measurement experiment. Then the AE source is located by using GCC method to estimate the time difference of each channel. Experiments are conducted on a T800 carbon fiber composite plate with the signal of lead break as simulating source. The experimental results show the accuracy and practicability of the proposed algorithm.