Pattern-Noise in Ultrasonic Inspection of Articles Made of Complexly Structured Materials

Resumo

Pattern-noise (PN) that occurs due to combined reflection of an ultrasonic probing signal from acoustic inhomogeneities in the material structure is an interference that conceals echo-signals from flaws. The most efficient method for extracting echo-signals from PN is multichannel spacetime signal processing (STSP). Different inspection purposes dictate different configurations of STSP schemes with the parameters that are determined by PN correlation characteristics. A theoretical model has been used to determine mutual PN correlation characteristics for the main types of transducers. The theoretical results have been confirmed experimentally.