Synthetic Aperture Focusing Imaging for Ultrasonic Testing of Concrete Defects
Due to the randomness of concrete,the ultrasonic waves propagate in concrete with strong attenuation,reflection,and scattering effects,the SNR(signal to noise ratio)of echo signal is low and the effective reflected signal with damage information is distorted by back-ground noise.Traditional ultrasonic signal processing is difficult to identify the specific infor-mation of defects.This article introduces the frequency domain synthetic aperture focusing al-gorithm to image the ultrasonic echo data picture.Numerical simulation and experimental re-search on concrete cavity defects are carried out at the same time.The trace equalization meth-od is used to enhance the deep signal of concrete,which improves the quality of defect echoes.Using frequency domain synthetic aperture imaging on multiple self-excited and self-receiving data,the imaging effect of ultrasound detection is significantly improved.The double-cavity concrete specimens were prefabricated to conduct the field test with a broadband narrow pulse probe.The results were basically consistent with the numerical simulation results.It is proved that synthetic aperture focusing technology can make the diffraction wave of defects converge well and effectively improve the resolution of small aperture ultrasonic probe.
万方数据
维普
