ANALYSIS OF FREE VIBRATIONS FOR RAYLEIGH -
LAMB WAVES IN A MICROSTRETCH THERMOELASTIC
PLATE WITH TWO RELAXATION TIMES

Rajneesh Kumara and Geeta Partapb

UDC 536.21

The propagation of free vibrations in a 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 a 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.

Keywords: microstretch, secular equations, phase velocity, 
attenuation.
 
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. Published in 
Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 1, pp. 36-46, January-February, 
2009. Original article submitted December 12, 2006; revision submitted 
November 14, 2007.