基于小波包变换及互相关的古建木材声发射源定位研究

Study on acoustic emission source location of ancient building wood based on wavelet packet transform and cross correlation

为研究古建筑木构件在承载过程中产生损伤定位问题,利用铅芯折断在木材表面模拟损伤源结合声发射技术对产生的损伤源进行检测。对采集的声发射信号首先采用小波包分解重构对信号进行去噪处理,利用互相关技术对重构信号进行互相关分析进而确定信号到达各传感器时差,最后结合时差定位法对声发射源进行定位。试验结果表明:该方法可以有效提高损伤源的定位精度,理论值与实际位置相差很小,从而为准确地反演出声发射源提供有效途径。

In order to study the damage location of wood components of ancient buildings in the bearing process,the lead core fracture was used to simulate the damage source on the wood surface,and the damage source was detected by acoustic emission technology.Firstly,wavelet packet decomposition and reconstruction is used to denoise the collected acoustic emission signal,and then cross-correlation analysis is used to determine the time difference of the signal reaching each sensor.Finally,the acoustic emission source is located combined with the time difference location method.The experimental results show that this method can effectively improve the positioning accuracy of damage source,and the difference between the theoretical value and the actual position is very small,which provides an effective way for accurate inverse performance of acoustic emission source.