EXPERIMENTAL RESEARCH ON ULTRASONIC 2D SAFT OF CONCRETE ELEMENTS

摘要

Being a promising approach in ultrasonic NDT methods, synthetic aperture focusing technique (SAFT)subsequently focuses the data measured on an aperture to every point of the reconstructed imaging area through superposition of the time records. In order to validate the potential of this method in NDT of concrete elements,an experimental system is setup to perform cross-surface scan of the test specimen, an SAFT processing program is established to give a 2-D display of the inner structure of the specimen based on the measured backscattered ultrasonic signals. Two different concrete specimens were cast with embedded objects. Design of the inspection pulse, for example the pulse shape and central frequency is discussed. According to SAFT imaging algorithm, images of these concrete structure are pictured. Compared to original B-scan method, SAFT gives better imaging quality.