AN IMPROVED SAFT IMAGING METHOD FOR CONCRETE INSPECTION

摘要

Ultrasonic inspection for reinforced concrete structures is one of the most promising Nondestructive Testing(NDT) techniques. To show the inner content of concrete structures, ultrasonic pulse-echo method is a goo d choice. Synthetic Aperture Focusing Technique (SAFT) is employed here to improve the image resolution. To minimize the computational cost, a wave-modeling (WM) method is introduced. Through parameterizing the detected waveforms, large numbers of data received by transducers are represented by a few model parameters.The SAFT imaging concept could be greatly simplified, and the consuming computational resource would be reduced. Numerical simulation is carried out to demonstrate the validity of the proposed method. As the result shows, the improved SAFT method can eliminate pseudo-scattering effectively, improve the signal-noise ratio of the reconstructed image, and reduce computational cost for SAFT imaging process.