The Acousto-Ultrasonic Approach

Industrial application of acousto-ultrasonic signal quality and robust time-of-flight estimation for anisotropic materials

“…AU is applicable to a large range of NDE problems [1]; however, it was originally applied to the inspection and characterization of graphite-reinforced plastics (GRP). It was one of the few NDE techniques that could empirically correlate to mechanical strength, for both tensile [2] and compressive [3] test configurations.…”

Enhancement of Ultrasonic Images of Defects in 3-D Composite

“…The use of 3-D dry fiber preforms and the resin transform molding Ultrasonic methods for qualitative and/or quantitative determination of the presence and the effects of defects in 2-D composite materials have been continuously developed over a number of years and are reviewed periodically [4]. While new quantitative ultrasonic methods are introduced for assessment of the presence of composite material defects [5][6][7][8] and for determining the mechanical performance of composite materials [9,10], the fundamental ultrasonic NDE methods, pulse-echo and through-transmission, have not significantly changed since their original inception. The changes which have occurred are primarily in the quality of the electronic components, such as the transducers and the pulser receivers, the mechanical devices for positioning the transducer, such as the scanning bridge, and the use of computerized control.…”

Characterization of adhesively bonded joints using acousto-ultrasonics

“…Although the transmitting transducer injects longitudinal waves normal to the joint specimen surface, the sound waves radiated into the material will produce oblique reflections and shear waves [80]. The resultant stress waves which consist of longitudinal and transverse components then undergo multiple reflections at the boundary surfaces of the specimen and interact with a significant fraction of the bond line volume that lies in their path.…”

“…Vary [4,80] described the stress wave factor as a relative measure of stress wave energy transmission. His hypothesis was that the decrease in stress wave energy flow corresponds to the decrease in fracture resistance of materials.…”