Generalized thermoelastic waves in homogeneous isotropic plates

The propagation of thermoelastic waves in homogeneous isotropic plate subje cted to stress-free and rigid insulated and isothermal conditions is invest igated in the context of conventional coupled thermoelasticity (CT), Lord-S hulman (LS), Green-Lindsay (GL), and Green-Nagdhi (GN) theories of thermoel asticity. Secular equations for the plate in closed form and isolated mathe matical conditions for symmetric and skew-symmetric wave mode propagation i n completely separate terms are derived. It is shown that the motion for SH modes gets decoupled from the rest of the motion and remains unaffected du e to thermo-mechanical coupling and thermal relaxation effects. The phase v elocities for SH modes have also been obtained. The results for coupled and uncoupled theories of thermoelasticity have been obtained as particular ca ses from the derived secular equations. At short wavelength limits the secu lar equations for symmetric and skew-symmetric waves in a stress-free insul ated and isothermal plate reduce to Rayleigh surface waves frequency equati ons. Finally, the numerical solution is carried out for aluminum-epoxy comp osite material and the dispersion curves for symmetric and skew-symmetric w ave modes are presented to illustrate and compare the theoretical results; (C) 2000 Acoustical Society of America. [S0001-4966(00)01108-5].