• Title/Summary/Keyword: thermoelastic

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Effect of magnetic field and gravity on thermoelastic fiber-reinforced with memory-dependent derivative

  • Mohamed I.A. Othman;Samia M. Said;Elsayed M. Abd-Elaziz
    • Advances in materials Research
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    • v.12 no.2
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    • pp.101-118
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    • 2023
  • The purpose of this paper is to study the effects of magnetic field and gravitational field on fiber-reinforced thermoelastic medium with memory-dependent derivative. Three-phase-lag model of thermoelasticity (3PHL) is used to study the plane waves in a fiber-reinforced magneto-thermoelastic material with memory-dependent derivative. A gravitating magneto-thermoelastic two-dimensional substrate is influenced by both thermal shock and mechanical loads at the free surface. Analytical expressions of the considered variables are obtained by using Laplace-Fourier transforms technique with the eigenvalue approach technique. A numerical example is considered to illustrate graphically the effects of the magnetic field, gravitational field and two types of mechanical loads(continuous load and impact load).

Thermoelastic Instability of the Layer Sliding between Two Non-conducting Half-planes (비전도 반평판 사이에서 미끄럼 운동하는 평판 층의 열탄성 불안정성)

  • 하태원;조용구;김흥섭;이정윤;오재응
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.483-488
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    • 2003
  • Frictional heating in brakes causes thermoelastic distortion of the contacting bodies and hence affects the contact pressure distribution. The resulting thermo-mechanical coupling can cause thermoelastic instability (TEI) if the sliding speed is sufficiently high, leading to non-uniform heating called hot spots and low frequency vibration known as hot judder. The vibration of brakes to the known phenomenon of frictionally-excited thermoelastic instability is estimated studying the interface temperature and pressure evolution with time. A simple model has been considered where a layer with half-thickness ${\alpha}$ slides with speed V between two half-planes which are rigid and non-conducting. The advantage of this properly simple model permits us to deduce analytically the critical conditions for the onset of instability, which is the relation between the critical speed and the growth rate of the interface temperature and pressure. Symmetrical component of pressure and temperature distribution at the layer interfaces can be more unstable than antisymmetrical component. As the thickness ${\alpha}$ reduces, the system becomes more apt to thermoelastic instability. Moreover, the evolution of the system beyond the critical conditions has shown that even if low frequency perturbations are associated with low critical speed, it might be less critical than high frequency perturbations if the working sliding speed is much larger than the actual critical speed of the system.

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Thermoelastic Instability of the Layer Sliding between Two Rigid Non-conducting Half-planes (단단한 비전도 반평판 사이에서 미끄럼 운동하는 평판층의 열탄성 불안정성)

  • 오재응;하태원;조용구;김흥섭;이정윤
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.114-121
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    • 2004
  • Frictional heating in brakes causes thermoelastic distortion of the contacting bodies and hence affects the contact pressure distribution. The resulting thermo-mechanical coupling can cause thermoelastic instability (TEI) if the sliding speed is sufficiently high, leading to non-uniform heating called hot spots and low frequency vibration known as hot judder. The vibration of brakes to the known phenomenon of frictionally-excited thermoelastic instability is estimated studying the interface temperature and pressure evolution with time. A simple model has been considered where a layer with half-thickness$\alpha$slides with speed V between two half-planes which are rigid and non-conducting. The advantage of this properlysimple model permits us to deduce analytically the critical conditions for the onset of instability, which is the relation between the critical speed and the growth rate of the interface temperature and pressure. Symmetrical component of pressure and temperature distribution at the layer interfaces can be more unstable than antisymmetrical component. As the thickness $\alpha$ reduces, the system becomes more apt to thermoelastic instability. For perturbations with wave number smaller than the critical$m_{cr}$ the temperature increases with m vice versa for perturbations with wave number larges than $m_{cr}$ , the temperature decreases with m.

Decaying temperature and dynamic response of a thermoelastic nanobeam to a moving load

  • Zenkour, Ashraf M.;Abouelregal, Ahmed E.
    • Advances in Computational Design
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    • v.3 no.1
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    • pp.1-16
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    • 2018
  • The decaying temperature and dynamic response of a thermoelastic nanobeam subjected to a moving load has been investigated in the context of generalized theory of nonlocal thermoelasticity. The transformed distributions of deflection, temperature, axial displacement and bending moment are obtained by using Laplace transformation. By applying a numerical inversion method, the results of these fields are then inverted and obtained in the physical domain. Also, for a particular two models, numerical results are discussed and presented graphically. Some specific and special results are derived from the current study.

고속전철용 디스크 브레이크의 열탄성 마멸에 관한 수치적 연구

  • 황준태;김청균
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.11a
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    • pp.269-275
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    • 1999
  • This paper presents the results of thermoelastic wear phenomena in ventilated disk brakes for a high-speed train using finite element method. The computed results show that the sinusoidal distortions due to non-uniform distributions of temperature profiles may lead to thermoelastic wears at the rubbing surface. This may decrease the life of a disk brake and produce micro-cracks, noise and squeals between two rubbing surfaces.

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Thermal stresses in a non-homogeneous orthotropic infinite cylinder

  • Edfawy, E.
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.841-852
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    • 2016
  • The present paper is concerned with the investigation of propagation of thermoelastic media, the finite difference technique is used to obtain the solution for the uncoupled dynamic thermoelastic stress problem in a non-homogeneous orthrotropc thick cylindrical shell. In implementing the method, the linear dynamic thermoelasticity equations are used with the appropriate boundary and initial conditions. Thermal shock stress becomes of significant magnitude due to stress wave propagation which is initiated at the boundaries by sudden thermal loading. Numerical results have been given and illustrated graphically in each case considered. The presented results indicate that the effect of inhomogeneity is very pronounced.

Relaxed Saint-Venant principle for thermoelastic micropolar diffusion

  • Marin, Marin;Abbas, Ibrahim;Kumar, Rajneesh
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.651-662
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    • 2014
  • The main goal of this study is to extend the domain of influence result to cover the micropolar thermoelastic diffusion. So, we prove that for a finite time t>0 the displacement field $u_i$, the microrotation vector ${\varphi}_i$, the temperature ${\theta}$ and the chemical potential P generate no disturbance outside a bounded domain $B_t$.

Thermomechanical interactions in a transversely isotropic magneto thermoelastic solids with two temperatures and rotation due to time harmonic sources

  • Lata, Parveen;Kaur, Iqbal
    • Coupled systems mechanics
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    • v.8 no.3
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    • pp.219-245
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    • 2019
  • The present research deals in two dimensional (2D) transversely isotropic magneto generalized thermoelastic solid without energy dissipation and with two temperatures due to time harmonic sources in Lord-Shulman (LS) theory of thermoelasticity. The Fourier transform has been used to find the solution of the problem. The displacement components, stress components and conductive temperature distribution with the horizontal distance are calculated in transformed domain and further calculated in the physical domain numerically. The effect of two temperature are depicted graphically on the resulting quantities.

Effect of thermal laser pulse in transversely isotropic Magneto-thermoelastic solid due to Time-Harmonic sources

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Coupled systems mechanics
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    • v.9 no.4
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    • pp.343-358
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    • 2020
  • The present research deals with the time-harmonic deformation in transversely isotropic magneto thermoelastic solid with two temperature (2T), rotation due to inclined load and laser pulse. Generalized theory of thermoelasticity has been formulated for this mathematical model. The entire thermo-elastic medium is rotating with uniform angular velocity and subjected to thermally insulated and isothermal boundaries. The inclined load is supposed to be a linear combination of a normal load and a tangential load. The Fourier transform techniques have been used to find the solution to the problem. The displacement components, stress components, and conductive temperature distribution with the horizontal distance are computed in the transformed domain and further calculated in the physical domain using numerical inversion techniques. The effect of angle of inclination of normal and tangential load for Green Lindsay Model and time-harmonic source for Lord Shulman model is depicted graphically on the resulting quantities.

A thermoelastic simulation on the (100) Si-wafer ((100) 실리콘 웨이퍼에 대한 열탄성모사)

  • Doo Jin Choi;Hyun Jung Woo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.1
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    • pp.71-75
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    • 1994
  • In this study, a thermoelastic stress index of (100) oriented single crystalline silicon wafer and a relationship between thermal stress and critical plastic deformation temperatures were simulated. The simulated results for the thermoelastic stress index indicated a maximum value on <110> direction and a minimum on <100>. Then, it could be predicted that silicon wafer is plastically deformable over 1000 K, based on the relationship between the thermal stress derived from the thermoelastic stress index and the critical plastic deformation temperature.

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