ht. 1. Engng Sci. Vol. 28, No. 6, pp. 547-556, 1990 OIEO-7225/W $3.00 + 0.00 Printed in Great Britain. All rights reserved Copyright @I 1990 Pergamon Press plc TRANSIENT GENERALISED MAGNETOTHERMO-ELASTIC WAVES IN A ROTATING HALF-SPACE DAYAL CHAND, J. N. SHARMA and S. P. SUDt Regional Engineering College, Hamirpur (HP)-177 01, India AbshPrt-The present paper deals with the investigations of the distribution of deformation, temperature, stresses and magnetic field in a homogeneous isotropic, thermally and electrically conducting, uniformly rotating elastic half-space, in contact with vacuum, due to (i) normal load and (ii) impulsive load, at the plane boundary, in the context of generalised theory of thermoelasticity. The Laplace transform on time has been used to obtain the solutions. Because “second sound” effects are short-lived, so small time approximations have been considered. The standard results of the previous investigations have also been deduced as particular cases. 1. INTRODUCTION Kaliski and Nowacki [l] studied the magneto-thermoelastic disturbances in a perfectly conducting elastic half-space, in contact with vacuum, due to an applied thermal disturbance on the plane boundary, in the absence of the coupling between temperature and the strain fields. Massalas and Dalmangas [2,3] also considered the problems by taking into ccount the thermo-mechanical couplings. The problem [2] was extended to generalised thermoelasticity theory developed by Green and Lindsay [4], involving two relaxation times by Chatterjee and Roychoudhuri [5]. Roychoudhuri and Debnath [6] studied the magnetothermo-elastic plane waves in a rotating media. Sharma and Chand [7] studied the transient magnetothermoelastic waves in the context of generalised theory of thermoelasticity developed by Lord and Shulman PI. In the present paper the distribution of deformation, temperature, stresses and perturbed magnetic field due to (i) normal load and (ii) impulsive load acting on the plane boundary by employing the generalised theory of thermoelasticity [8]. The Laplace transform technique [9] is used to obtain the solutions. As the “second sound” effects are shortlived, so small time approximations have been considered. 2. THE PROBLEM AND ITS SOLUTION We consider a homogeneous isotropic, thermally and electrically conducting elastic medium at uniform temperature T,, in contact with vacuum. We assume that the medium is rotating with uniform angular velocity a about x+&s and also an initial magnetic field & is acting along x3-axis. When the medium undergoes dynamical deformation, the two additional terms which do not appear in the non-rotating medium: (i) the time dependent part of centripetal acceleration P X (S2 X u) and (ii) the Coriolis acceleration 2a X i where u is the displacement vector, will also appear in the governing equation. The governing equations of electrodynamics of slowly moving bodies, equation of motion, and heat conduction equation of linear generalised thermoelasticity in the absence of body forces and heat sources are v X II = 4JrJ/c, VxE=-p,,ti/c V.h=O, E = -pc,(i x H,J/c (1) pvsl+(~+y)V(v.u)+~ 41t[(VXh)xH,]-yV8=p[ii+QX(QXu)+2Qxi] (2) t Department of Physics, H.P. University, Shimla (HP)-171 005, India. 547