Statistically Characterizing Void Density by Ultrasonic Speckles
Sprache des Vortragstitels:
EUROCAST 2015; Fifteenth International Conference on Computer Aided Systems Theory
Sprache des Tagungstitel:
We investigate the gradual emergence of so--called ultrasonic (US) speckles as a hint to degradation processes deep in the volume of a specimen. Voids within the volume of a specimen are caused by the combined action of thermal or electrical loads the specimen is subjected to during overload cycles it might experience as part of normal operation. These scatterers are typically too small to be directly imaged by ultrasound techniques. However, due to their spatial density evolving over time (over load cycles) they expose themselves by gradually forming these revealing US--speckles that increase in contrast over time. We can show that the speckle contrast is a good measure of the average total volume density of scattering voids and thus of the onset and evolution of delaminations via partially developed speckles.