Abstracto

Damage Identification using SAFT Algorithm

Needhi Kotoky, Shivang Shekhar

For the detection of defects and the characterization of materials in concrete ultrasonic testing is an established nondestructive technique. Reconstruction by the synthetic aperture focusing technique (SAFT) is used in ultrasonic testing as it offers a general solution to the difficulties encountered while testing. SAFT algorithm creates a high-resolution image by numerically superimposing pulse-echo signals measured at several positions. Signals are focused in the image to every image point, and structural noise is suppressed by spatial superposition. Hence, a large virtual transducer with variable focus is synthesized. A synthetic aperture imitates a transducer by sampling its area at many points, either by an array of transducers measuring simultaneously, or by a single transducer approaching the aperture points in succession. In this paper, a diagnostic tool for detection and assessment of reflectors for automated large area nondestructive inspection of concrete structures using one-dimensional array is described to overcome limitations of point-bypoint inspection technique. The apertures considered in this paper are planar and circular.