Adnan H. Nayfeh

Bio: Adnan H. Nayfeh is an academic researcher from University of California, San Diego. The author has contributed to research in topics: Longitudinal wave & Thermal conduction. The author has an hindex of 4, co-authored 6 publications receiving 206 citations.

Transient thermo-elastic waves in a half-space with thermal relaxation

Abstract: We use the Cagniard-De Hoop method to develop the displacement and temperature fields in a half-space subjected on its free surface to an instantaneously applied heat source. We include in our analysis the thermal relaxation time of heat conduction, which insures that the termal waves propagate with a finite signal speed. We express our solution in terms of a small thermo-elastic coupling coefficient, and obtain explicit expressions for the wave-speeds and wave-amplitudes. Due to the existence of the thermal damping, we give only the short-time solution. We then present numerical results for the dilatation and the temperature so as to illustrate the salient features of the problem.

On martin's lower bound for response time of impulsively loaded rigid-plastic structures.

Abstract: : Martin has given a lower bound for the time that an impulsively loaded rigid-plastic structure takes to come to rest ('response time'). In the evaluation of this bound, and arbitrary fixed yield mechanism is used. Even if this differs from the yield mechanisms activated in the actual motion of the structure, the lower bound may coincide with the actual response time. Cases in which this coincidence occurs are more closely investigated in the present paper, and it is shown that they must be regarded as highly exceptional. (Author)

Extended irreversible thermodynamics

Abstract: Our aim is to propose a theory which goes beyond the classical formulation of thermodynamics. This is achieved by enlarging the space of basic independent variables, through the introduction of non-equilibrium variables, such as the dissipative fluxes appearing in the balance equations. The next step is to find evolution equations for the dissipative fluxes. Whereas the evolution equations for the classical variables are given by the usual balance laws, no general criteria exist concerning the evolution equations of the dissipative fluxes, with the exception of the restrictions imposed on them by the second law of thermodynamics.

The elastic wave motions for a photothermal medium of a dual-phase-lag model with an internal heat source and gravitational field

Abstract: In this work, the dual-phase-lag (DPL) heat transfer model is introduced to study the problem of an isotropic generalized thermoelastic medium with an internal heat source that is moving with a con...

The effect of rotation on the reflection of magneto-thermoelastic waves under thermoelasticity without energy dissipation

Abstract: In this paper reflection of magneto-thermoelastic waves is employed to study the effect of rotation and the magnetic field on the plane harmonic waves of a rotating semi-infinite elastic solid nearby a vacuum under Green and Naghdi theory. The expressions for the reflection coefficients, which are the ratios of the amplitudes of the reflected waves to the amplitude of the incident wave, are obtained. The effect of rotation, the magnetic field, coupling parameter and frequency on the reflection ratios are illustrated graphically. Comparisons are made with the results predicted by GN theory of type II in the presence and absence of rotation and magnetic field. A comparison is also made with the results predicted by GN theory of types II and III in the presence of the magnetic field and rotation.