Super resolution imaging of concrete

In this paper, ultrasonic wave is used for nonde-structive testing of concrete structures. At present, most of the ultrasound imaging on the market uses full matrix full focus imaging mode. A time reversal algorithm to improve the imaging resolution of defects is proposed. The traditional ultrasonic imaging algorithm follows the Rayleigh rule, and the imaging resolution is related to the system frequency. The higher the frequency, the higher the resolution, but the concrete material structure is complex, the higher the ultrasonic frequency, the stronger the attenuation ability in the medium and the shorter the detection distance, so the low frequency ultrasound must be used. The time reversal algorithm can improve the resolution of imaging without changing the system frequency and ensuring the detection range. The principle of adaptive focusing is used to achieve high resolution defect detection. In this paper, COMSOL software is used to simulate the defects of concrete structure and piezoelectric ultrasonic excitation equipment, and the collected signals are processed to achieve super-resolution imaging.