Elastic waves in elongated bars exhibit complex dispersion, including propagating and non-propagating modes. We investigated the feasibility of extracting non-propagating modes through the electromechanical impedance (EMI) method in a rectangular bar structure through numerical simulation. First, the dispersion curves and mode shapes were computed to identify non-propagating modes. Second, a finite element model consisting of a piezoelectric lead zirconate titanate (PZT) patch and a rectangular bar was established to understand structural responses in the frequency-wavenumber (f-k) domain and the corresponding conductance spectra from the EMI measurements. Zero-group-velocity (ZGV) and cut-off frequency resonances were identified in both EMI signature and structural responses. The paper demonstrated the potential of the proposed EMI technique to extract non-propagating modes in waveguide structures for quantitative nondestructive evaluation (NDE).
(1) Brum, J., Bernal, M., Gennisson, J. L., and Tanter, M., 2014, “In Vivo Evaluation of the Elastic Anisotropy of the Human Achilles Tendon Using Shear Wave Dispersion Analysis,” Phys. Med. Biol., 59(3), pp. 505–523.
(2) Damljanović, V., and Weaver, R. L., 2004, “Propagating and Evanescent Elastic Waves in Cylindrical Waveguides of Arbitrary Cross Section,” The Journal of the Acoustical Society of America, 115(4), pp. 1572–1581.
(3) Laurent, J., Royer, D., and Prada, C., 2020, “In-Plane Backward and Zero Group Velocity Guided Modes in Rigid and Soft Strips,” The Journal of the Acoustical Society of America, 147(2), pp. 1302–1310.
(4) Sun, F. P., and Rogers, C. A., “Coupled Electro-Mechanical Analysis of Adaptive Material Systems — Determination of the Actuator Power Consumption and System Energy Transfer,” p. 9.
(5) Zhu, X., and Lanza di Scalea, F., 2016, “Sensitivity to Axial Stress of Electro-Mechanical Impedance Measurements,” Exp Mech, 56(9), pp. 1599–1610.
(6) Laurent, J., Royer, D., and Prada, C., 2020, “In-Plane Backward and Zero Group Velocity Guided Modes in Rigid and Soft Strips,” The Journal of the Acoustical Society of America, 147(2), pp. 1302–1310.
(7) APC International, Ltd. (2016) Physical and piezoelectric properties of APC materials https://www.americanpiezo.com/apcmaterials/piezoelectric-properties.html. Accessed 22 February 2022
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