超声脉冲压缩法检测混凝土损伤的研究

为提高混凝土超声检测的信号噪声比,提高测量精度,研究脉冲压缩调频超声发射的方法。该方法发射具有包络的线性调频超声脉冲,在不提高发射声压的情况下增加了发射能量,可提高超声检测的有效作用距离和测量精度,提高信噪比。笔者给出脉冲压缩和解压的基本原理,设计了脉冲解压缩电路;经实验检测结果表明,脉冲压缩超声检测能在没有降低测量距离的情况下,明显提高检测的精度,检测到常规检测中不能发现的缺陷。

Study on Damage Detection of Concrete Based on Ultrasonic Pulse Compression Method

To improve the measuring accuracy and increase the signal-to-noise ratio(SNR)in ultrasonic detection of concrete damage,a frequency-modulated(FM)ultrasound transmission method was firstly developed.This method,due to transmitting an enveloped linear FM ultrasonic pulse,could enhance the emission energy without increasing the emission ultrasound pressure,and thus enhanced the effective disLance,measuring accuracy and signal-to-noise ratio.Then,the principles of pulse compression and decompression were discussed,and the electric circuit of pulse compression was devised.Experimental resuits show that pulse compression can improve measuring accuracy without reducing the effective distance.It can discover the flaws that can't be discovered by conventional detection methods.