Options
2001
Journal Article
Titel
Semi-analytical elastic wave-field modeling applied to arbitrarily oriented orthotropic media
Abstract
Three-dimensional elastic wavefield calculation is addressed for the case of orthotropic materials with arbitrary spatial orientation. Based on a mathematical formulation involving Green's dyadic displacement tensor function, appropriate evaluation yields a representation of the displacement vector of transducer wavefields in anisotropic media which is convenient for effective numerical computation. With respect to bulk wave propagation the numerical evaluation of Green's dyadic function is circumvented by applying a reciprocity-based approach, which is valid in the (point source) far-field. The presented formulation involves characteristic quantities obtained from plane wave theory and appears as a point source superposition representation including the respective point source directivities. Thus, it is in the same form as a corresponding formulation for scattered elastic wavefields presented previously [M. Spies, J. Acoust. Soc. Am., 107, 2755-2759 (2000)]. Focusing on orthotropic composite materials, numerical evaluation examples are presented for ultrasonic tranducer field patterns and time-dependent RF-pulse propagation.