Elastic Wave Diffraction Fields Generated by Surface Excitation of a Crystal

摘要

The angular spectrum theory is currently used to analyse the diffraction fields generated by a finite aperture source on surface of the anisotropic medium. Only is the anisotropy of the propagation velocity regarded in such a sclar theory. So this theory is insufficient and exists many shortcomings. Since the elastic wave in solid is the vector field, the diffraction patterns for various wave modes, various components of each mode and various excitated sources are different generally. The angular spectrum theory neglected actual physical field can only give a relative distribution of phenomenological field. According to the generalized excitation theory in our previous works, the diffraction elastic wave fields excitated by the surface finite-aperture source are obtained in this paper. As an example, the calculation results of the diffraction fields for YZ quartz are given and compared with that of the angular spectrum theory.