Magneto-thermo-elastic wave propagation in the generalized dynamical theory of thermo-elasticity type II

The propagation of plane waves in an infinite thermoelastic solid with finite electrical conductivity permeated by a primary uniform magnetic field has been investigated, using the thermo-elasticity theory (type II) of Green and Naghdi. It reveals that the magneto-thermo-elastic plane waves in thermo-elastic media (G-N model) undergo attenuation and dispersion in contrast to the purely coupled thermo-elastic waves in thermo-elasticity theory of type II (without energy dissipation), which are unattenuated and non-dispersive. The more general dispersion equation is analyzed to examine the effects of finite thermal wave speed of G-N theory, thermoelastic coupling and the external magnetic field on the phase velocity of the coupled waves and also on the specific energy loss. Cases of limitly low and high frequencies are also analyzed. Further, a graphical representation of the phase speed and attenuation factor versus frequency with and without magnetic field are presented.