G. Avdelas1, D. A. Sotiropoulos1
1Department of Engineering Sciences, Technical University of Crete, Chania 73100, Greece
Tóm tắt
A theory is developed for the mechanical characterization of planar bimaterial interfaces based on the simultaneous reflection of P and SV elastic waves. For perfect interfacial bond, the reflectivity R=RppRss−RspRps, for wave incidence in each of the two semi-infinite media, is proved to be independent of the medium containing the incident waves, if Snell’s law relates the angles of incidence in the media. Based on this result, it is proved that for imperfect bond this independence property of R is preserved only if R=0, which defines the Brewster wave number(s). Thus the Brewster wave number(s) offers a unified experimental approach for the nondestructive evaluation of material interfaces. An analytical formula is derived which relates the Brewster wave number(s) to the mechanical bond parameter of a one-parameter imperfect bond model. For a given Brewster wave number found experimentally, the bond parameter is determined explicitly and uniquely from this formula. Numerical examples are considered to show the range of existence of the Brewster wave number(s).
