Analysis of free vibrations for Rayleigh lamb waves in a micropolar viscoelastic plate

The propagation of free vibrations in a homogeneous isotropic micropolar viscoelastic plate subjected to stress free conditions is investigated. The secular equations for symmetric and skew symmetric wave mode propagation are derived. The regions of secular equations are obtained and special cases such as Lame modes, thin plate results and short wavelength waves are also discussed. At short wavelength limit, the secular equations for symmetric and skew symmetric waves in a stress free plate reduce to the Rayleigh surface wave frequency equation. The amplitudes of normal force stress, tangential force stress and tangential couple stress are obtained and depicted graphically. Finally, numerical solution is carried out for magnesium crystal composite material plate.