| Acousto-electromagnetic wave interaction occurs when an electromagnetic wave scatters from an object under seismic or acoustic illumination. The vibration of the object under acoustic excitation gives rise to a frequency modulated scattered field which depends on the object and both the electromagnetic and acoustic source parameters. Previous work in this area has been limited to analytical solutions for homogeneous, circular cylinders and limited experimental work for specific applications. The objective of this research is to accurately predict the first Doppler component of the frequency modulated scattered field for arbitrary two-dimensional objects.; A unique formulation of the problem, which is built on the analytical solution, is implemented in the finite-difference time-domain method. The result is a tool which is capable of predicting the Doppler component scattered from general two-dimensional objects. This more general model provides information on system feasibility and is a major step towards implementing the acousto-electromagnetic method in real-world systems.; Using the generalized model, the acousto-EM approach is also investigated for non-destructive evaluation applications. The Doppler component is inherently affected by the presence of interior flaws, which perturb the acoustic mode frequency and shape. Unique bistatic signatures for the Doppler component, which exhibit sensitivity to interior abnormalities, are presented. Depending on the flaw orientation, the target, and the mode of interest, the Doppler component can be orders of magnitude more sensitive than the unshifted electromagnetic fields scattered from the stationary target. A relative sensitivity parameter is introduced to quantify the improved sensitivity of the Doppler component relative to the unshifted fields; parameter values routinely indicate factors of ten improvement in sensitivity at certain bistatic angles. In addition, time-reversal focusing is used to locate regions of enhanced scattering, such as those surrounding a flaw, within the target. The results demonstrate that the Doppler component would be useful for detecting the presence of such abnormalities in a non-destructive evaluation system. |
