CE 5310 Lecture Notes - Lecture 14: Crc Press, Boca Raton, Florida, Rebar
Document Summary
In the land of the blind, the one eyed man is king -desiderius erasmus. The standard ultrasonic tools available for elastic homogenous materials typically fail to resolve critical defects in concrete due to background noise (figure 1). Stress wave propagation in a strongly non-homogenous material is a difficult problem. Aperture focusing technique (saft) is a useful tool to bridge the gap between complex generation/collection of data and simple presentation of results. The aperture, across a broad spatial area, is synthetically restricted to a single point. By using many sensing locations the structural noise decreases, while the coherent reflections remain consistent. Figure 1: standard ultrasonic pulse echo time signal in concrete with structural noise and reflections. In the current image algorithms many assumptions are made to increase the clarity of the generated image. Each assumption has various degrees of reliability and should be carefully considered as image methods are applied to new.
