The Brewster wave-number concept for elastodynamics

The existence of a Brewster wave number is demonstrated for the case of plane-wave reflection by a specularly smooth, planar interface joining two homogeneous, linearly elastic, isotropic solid half-spaces. Such a wave number is numerically shown to exist for two material combinations: steel-aluminum and steel-brass. The wave number can be such that plane waves are either propagating or evanescent. Since the calculated Brewster wave number is not dependent upon which of the two half-spaces contains the incident plane waves, it appears to be an intrinsic property of the bimaterial interface and hence may be useful in the characterization of such interfaces.