UDC 536.21

Rajneesh Kumara and Geeta Partapb

ANALYSIS OF FREE VIBRATIONS FOR RAYLEIGH - LAMB WAVES IN MICRO-S TRETCH THERMOELASTIC PLATE WITH TWO RELAXATION TIMES
The propagation of free vibrations in microstretch thermoelastic homogeneous isotropic plate subjected to stress free thermally insulated and isothermal conditions is investigated in the context of conventional coupled thermoelasticity (CT) and Green and Lindsay (G-L) theories of thermoelasticity. The secular equations for the microstretch thermoelastic plate in closed form for symmetric and skew-symmetric wave mode propagation in completely separate terms are derived. At short wavelength limits, the secular equations for both modes in stress free thermally insulated and isothermal homogeneous isotropic microstretch thermoelastic plate reduce to the Rayleigh surface wave frequency equation. The results for symmetric and skew-symmetric wave modes are computed numerically and presented graphically. The theory and numerical computations are found to be in close agreement. aDepartment of Mathematics, Kurukshetra University, Kurukshetra, Haryana, India; email: rajneesh_kuk@rediffmail.com; bDepartment of Mathematics, Dr. B. R. Ambedkar National Institute of Technology, Jalandhar, Punjab, India; email: pratapg@nitj.ac.in. Original article submitted December 12, 2006; revision submitted November 14, 2007.