基于巴克码编码脉冲压缩的混凝土超声检测仿真分析

Simulation Analysis of Ultrasonic Testing Based on Pulse Compression of Barker Coding for Concrete

混凝土的超声检测中,由于混凝土材料的非均质结构而造成的结构噪声是影响超声检测效果的重要因素之一。为了进一步提高超声检测信号的信噪比,提出应用具有良好的自相关特性以及噪声抑制优势的巴克码信号作为激励信号。设计和建立混凝土结构模型,进行仿真测试及检测结果的成像处理与分析,将本研究所提方法的成像结果与常规高斯脉冲反射法的成像结果进行对比。结果表明,通过对检测信号的脉冲压缩处理以及旁瓣抑制处理,有效压缩了脉冲宽度,提高了检测信号的时空分辨率,从而增强成像结果的信噪比;采用本研究方法处理后的成像结果信噪比提高了8.3 dB,成像质量明显提升。

In ultrasonic testing of concrete,structural noise caused by the heterogeneous structure of concrete materials is one of the important factors affecting the effectiveness of ultrasonic testing.In order to further improve the signal-to-noise ratio of ultrasonic testing signals,it is proposed to use Barker code signal as excitation signal,which has good autocorrelation characteristics and noise suppression advantages.A concrete structure model was designed and established for conducting simulation tests,and imaging processing and analysis of detection results.The imaging results by the proposed method were compared with those through the conventional Gaussian pulse reflection method.The results show that the spatiotemporal resolution of the detection signal is improved and related signal-to-noise ratio is enhanced because of the compressed pulse width and suppressed sidelobe in the detection signals.Moreover,with this method,the signal-to-noise ratio of the results is improved by 8.3 dB and the imaging quality is significantly promoted.