Generation of Axial Shear Acoustic Resonance by Magnetostrictively Coupled Emat
In this paper, we present a technique to generate the axial shear acoustic resonance in a cylindrical rod and pipe by a magnetostrictively coupled EMAT. The technique is based on the electromagnetic acoustic resonance (EMAR) [1–7]. The EMAR is a combination of the ultrasonic resonance technique and a noncontacting EMAT. The heavily and coherently overlapping echoes at a resonant state improves the signal-to-noise ratio to a large extent and compensates enough for the weak coupling efficiency with the EMATs. The EMAR method was first proposed by Filimonov et al.  and Nikiforenko et al. . In recent years, several researchers have developed this technique for the wide range of the noncontact inspection and materials characterization [3–7].
KeywordsResonant Frequency Attenuation Coefficient Peak Amplitude Field Dependence Resonant Mode
Unable to display preview. Download preview PDF.
- 1.S. A Filimonov, B. A. Budenkov, and N. A Glukhov, Sov. J. Nondestr. Test., 1, 102 (1971).Google Scholar
- 2.Z. G. Nikiforenko, N. A Glukhov, and I.I. Averbukh, Sov. J. Nondestr. Test., 4,427 (1971).Google Scholar
- 3.K. Kawashima, J. Acoust. Soc. Am., 87, 681 (1990).Google Scholar
- 5.W. Johnson, B. A. Auld, and G. A Alers, in Review of Progres in QNDE, Vol. 13, eds. D. O. Thompson and D. E. Chimenti (Plenum, New York, 1994), p. 1603.Google Scholar
- 10.H. Ogi, M. Hirao, and K. Minoura, to be submitted.Google Scholar