Reflection of plane waves in magneto-micropolar thermoelastic medium with voids and one relaxation time due to gravity and two-temperature theory

2020 ◽  
Author(s):  
Mohamed I. M. Hilal ◽  
Elsayed M. Abd-Elaziz ◽  
S. A. Hanoura
Keyword(s):  
Relaxation Time ◽  
Plane Waves ◽  
Thermoelastic Medium ◽  
Two Temperature

Reflection of plane waves in thermoelastic medium with double porosity

2016 ◽  
Vol 12 (4) ◽  
pp. 748-778 ◽  
Author(s):  
Rajneesh Kumar ◽  
Richa Vohra ◽  
M.G. Gorla
Keyword(s):  
Relaxation Time ◽  
Earthquake Engineering ◽  
Plane Waves ◽  
Practical Importance ◽  
Double Porosity ◽  
Angle Of Incidence ◽  
Amplitude Ratios ◽  
Thermoelastic Medium ◽  
Content Type ◽  
The Earth

Purpose The purpose of this paper is to study the reflection of plane waves in thermoelastic medium with double porosity structure. Design/methodology/approach A two-dimensional model is considered of an isotropic thermoelastic half-space with double porosity. Thermoelasticity with one relaxation time given by Lord and Shulman (1967) has been used to study the problem. It is found that there exists four coupled longitudinal waves, namely, longitudinal wave (P), longitudinal thermal wave (T), longitudinal volume fractional wave corresponding to pores (PVI) and longitudinal volume fractional wave corresponding to fissures (PVII), in addition to an uncoupled transverse wave (SV). Findings The formulae for amplitude ratios of various reflected waves are obtained in closed form. It is found that these amplitude ratios are functions of angle of incidence. Effect of porosity and thermal relaxation time is shown graphically on the amplitude ratios with angle of incidence for a particular model. Originality/value Reflection of plane waves is of great practical importance. There are many organic and inorganic deposits beneath the earth surface. Wave propagation is the simplest and most economical technique to detect these. The model discussed in the present paper can provide useful information for experimental researchers working in the field of geophysics and earthquake engineering, along with seismologist working in the field of mining tremors and drilling into the crust of the earth.

A novel model of plane waves of two-temperature fiber-reinforced thermoelastic medium under the effect of gravity with three-phase-lag model

2019 ◽  
Vol 29 (12) ◽  
pp. 4788-4806 ◽  
Author(s):  
Mohamed I.A. Othman ◽  
Samia Said ◽  
Marin Marin
Keyword(s):  
Energy Dissipation ◽  
Plane Waves ◽  
Mode Analysis ◽  
Phase Lag ◽  
Fiber Reinforced ◽  
Thermoelastic Medium ◽  
Content Type ◽  
Three Phase ◽  
Novel Model ◽  
Two Temperature

Purpose In the present paper, the three-phase-lag (3PHL) model, Green-Naghdi theory without energy dissipation (G-N II) and Green-Naghdi theory with energy dissipation (G-N III) are used to study the influence of the gravity field on a two-temperature fiber-reinforced thermoelastic medium. Design/methodology/approach The analytical expressions for the displacement components, the force stresses, the thermodynamic temperature and the conductive temperature are obtained in the physical domain by using normal mode analysis. Findings The variations of the considered variables with the horizontal distance are illustrated graphically. Some comparisons of the thermo-physical quantities are shown in the figures to study the effect of the gravity, the two-temperature parameter and the reinforcement. Also, the effect of time on the physical fields is observed. Originality/value To the best of the author’s knowledge, this model is a novel model of plane waves of two-temperature fiber-reinforced thermoelastic medium, and gravity plays an important role in the wave propagation of the field quantities. It explains that there are significant differences in the field quantities under the G-N II theory, the G-N III theory and the 3PHL model because of the phase-lag of temperature gradient and the phase-lag of heat flux.

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