Ultrasonic defect characterization with a dynamic adaptive focusing system

Study of phased array techniques for concrete inspection

“…This enhances and concentrates the energy at a selected depth which increases the resolution and signal to noise ratio. Preliminary measurements in transmission [3] have successively shown the ability of focusing an ultrasonic beam in a concrete structure. Compared to multi probes reconstruction phased array technique takes the advantage of a concentrate focal spot transmitting higher energy on a selected region.…”

“…Early experimental measurements have been carried out on a concrete block of 800x800x600 mm 3 An artificial crack composed of four facets with different orientations has been included in the block. Each facet noted Pi on Fig.…”

NDT of Specimen of Complex Geometry Using Ultrasonic Adaptive Techniques - The F.A.U.S.T. System

“…The dynamic adaptive system relies on optimized phased array transducers [3], connected to a multi-channel acquisition system, supplying delay and amplitude laws to form the ultrasonic beam. A diffraction model [4], based on the Rayleigh integral formulation extended to liquid-solid interface, is used both to calculate theoretical delay laws and ultrasonic fields radiated by phased array transducers.…”

Modeling of ultrasonic fields and their interaction with defects

“…y ) (the x-axis being in the plane o f incidence while the y-axis being normal to it) as ( 9 ) E ( x , y , t ) = defec1 where @ denotes temporal convolution.…”