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Quantitative modeling and experimental analysis of the physical properties of electromagnetic-ultrasonic transducers.

Quantitative Modellierung und experimentelle Analyse der physikalischen Eigenschaften elektromagnetischer Ultraschallwandler
: Wilbrand, A.

Review of Progress in Quantitative Nondestructive Evaluation. 7A
New York: Plenum Publishing, 1988 (Review of Progress in Quantitative Nondestructive Evaluation 7A)
Annual Review of Progress in Quantitative Nondestructive Evaluation <14, 1987, Williamsburg/Va.>
Conference Paper
Fraunhofer IZFP ()
Absolutmessung; Eisen; Empfindlichkeit; Frequenzabhängigkeit; Leitfähigkeit(elektrisch); Linienwandler; Magnetostriktion; Metall; Modell(mathematisch); Permeabilität; Richtcharakteristik; Transversalwelle; Ultraschall; Ultraschallwandlung(berührungslos); Ultraschallwandlung(elektromagnetisch); Untersuchung(experimentell); Werkstoff(magnetisch); Winkelprüfkopf

The performance of electromagnetic-ultrasonic (EMUS) transducers on electrically conducting, ferromagnetic elastic material is theoretically described for transmission and reception of bulk waves and Rayleigh waves. The transduction process is modeled through the superposition of a Lorentz force mechanism, a magnetization mechanism and a magnetostriction mechanism. Directivity patterns and sensitivities are calculated for transducers with a given rf coil geometry and magnetic bias field orientation. From the sensitivities of the transmitting and the receiving transducer the transfer impedance of the whole system is obtained. Transfer impedances of various transducer configurations for the excitation of shear waves in iron have been measured as a function of frequency, angle of incidence, and bias field strength and have been compared to the theoretical results. From the out-come of this study, it is concluded that the transducer model gives a valid description of the physical laws unde rlying the transducer behaviour and can be used for quantitative estimations in EMUS probe design. (IZFP)