Ultrasonic field patterns and broadband imaging-simulations in transversely isotropic media

At last year's conference a theory of elastic wave propagation in transversely isotropic media has been presented. In order to provide information from a practical point of view the theory has been evaluated to yield field patterns of Gaussian Wave Packets (GWPs) in unidirectional graphite-epoxy as well as centrifugally cast stainless steel. Numerical results are given for various angles of incidence at fixed fiber orientation and vice versa. The plane wave spectral decomposition of Green's dyadic and triadic functions has been used to derive the algorithm of forward-backward-propagation of elastic wavefields yielding a simple solution to the inverse problem, the socalled elastodynamic holography. With this basic imaging technique, field distributions of GWPs are propagated forth and back. Finally the simulations, being evaluated in frequency domain, are performed at multiple frequencies thus in principle making up a mode-matched RT-SAFT in negliction of the vector scattering amplitude s.