钢板声发射时间反转聚焦增强定位方法

声发射检测方法具有实时动态监测优点,应用越来越广泛,但是对声源的定位始终没有更大的突破。在钢板声发射检测中,提出一种基于时间反转理论的声发射源准确定位的方法。由于声发射检测是一种被动检测技术,结合时间反转聚焦理论,推导出对声源信号实现时间反转聚焦增强处理方法,可增强检测信号中声源幅值,提高信噪比;然后根据声源信号到达时间推算出声源聚焦时刻,利用弹性波传播理论对传感器监测区域重建信号传播波动图,显示出声源位置和区域;最后通过实验测试对该方法进行验证,结果表明该方法能有效提高损伤声源信号的能量,对检测区域的信号重建和定位显示准确地给出损伤声源位置。

Location method of acoustic emission by time reversal focusing and enhancing for steel plate

Acoustic emission (AE) testing method can realize real time dynamic monitoring, thus it has been widely applied. However, there is still no breakthrough in the location of AE source. A method based on time reversal theory is proposed to accurately locate the acoustic emission source on the detection of steel plate. Because acoustic emission testing is a passive monitoring method, the processing method of time reversal focusing and enhancing to AE source signal can be achieved according to time reversal theory, by which AE source signal will be amplified and the signal to noise ratio (SNR) will be enhanced. Then the AE source focusing time can be calculated according to the AE source arriving time, and the signal propagation wave image can be reconstructed by taking advantage of the elastic wave propagation theory, and the position of AE source is revealed through the signal focusing. Finally, the method has been verified through experiments, and the results show that the proposed method can effectively improve signal energy of the damage source, and the position of the damage source can be shown accurately through signal reconstruction and location in the detection area.