• 제목/요약/키워드: memory-dependent derivative

검색결과 12건 처리시간 0.024초

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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    • 제12권2호
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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).

Transient memory response of a thermoelectric half-space with temperature-dependent thermal conductivity and exponentially graded modulii

  • Ezzat, Magdy A.
    • Steel and Composite Structures
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    • 제38권4호
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    • pp.447-462
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    • 2021
  • In this work, we consider a problem in the context of thermoelectric materials with memory-dependent derivative for a half space which is assumed to have variable thermal conductivity depending on the temperature. The Lamé's modulii of the half space material is taken as a function of the vertical distance from the surface of the medium. The surface is traction free and subjected to a time dependent thermal shock. The problem was solved by using the Laplace transform method together with the perturbation technique. The obtained results are discussed and compared with the solution when Lamé's modulii are constants. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions. Affectability investigation is performed to explore the thermal impacts of a kernel function and a time-delay parameter that are characteristic of memory dependent derivative heat transfer in the behavior of tissue temperature. The correlations are made with the results obtained in the case of the absence of memory-dependent derivative parameters.

Modeling of memory-dependent derivative in a rotating magneto-thermoelastic diffusive medium with variable thermal conductivity

  • Said, Samia M.;Abd-Elaziz, Elsayed M.;Othman, Mohamed I.A.
    • Steel and Composite Structures
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    • 재36권6호
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    • pp.617-629
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    • 2020
  • The purpose of this paper is to depict the effect of rotation and initial stress on a magneto-thermoelastic medium with diffusion. The problem discussed within memory-dependent derivative in the context of the three-phase-lag model (3PHL), Green-Naghdi theory of type III (G-N III) and Lord and Shulman theory (L-S). Analytical expressions of the considered variables are obtained by using Laplace-Fourier transforms technique. Numerical results for the field quantities given in the physical domain and illustrated graphically in the absence and presence of a magnetic field, initial stress as well as the rotation. The differences in variable thermal conductivity are also presented at different parameter of thermal conductivity. The numerical results of the field variables are presented graphically to discuss the effect of various parameters of interest. Some special cases are also deduced from the present investigation.

Thermoelectric viscoelastic materials with memory-dependent derivative

  • Ezzat, Magdy A.;El Karamany, Ahmed S.;El-Bary, A.A.
    • Smart Structures and Systems
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    • 제19권5호
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    • pp.539-551
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    • 2017
  • A mathematical model of electro-thermoelasticity has been constructed in the context of a new consideration of heat conduction with memory-dependent derivative. The governing coupled equations with time-delay and kernel function, which can be chosen freely according to the necessity of applications, are applied to several concrete problems. The exact solutions for all fields are obtained in the Laplace transform domain for each problem. According to the numerical results and its graphs, conclusion about the proposed model has been constructed. The predictions of the theory are discussed and compared with dynamic classical coupled theory. The result provides a motivation to investigate conducting thermoelectric viscoelastic materials as a new class of applicable materials.

Fiber-reinforced micropolar thermoelastic rotating Solid with voids and two-temperature in the context of memory-dependent derivative

  • Alharbi, Amnah M.;Said, Samia M.;Abd-Elaziz, Elsayed M.;Othman, Mohamed I.A.
    • Geomechanics and Engineering
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    • 제28권4호
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    • pp.347-358
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    • 2022
  • The main concern of this article is to discuss the problem of a two-temperature fiber-reinforced micropolar thermoelastic medium with voids under the effect rotation, mechanical force in the context four different theories with memory-dependent derivative (MDD) and variable thermal conductivity. The three-phase-lag model (3PHL), dual-phase-lag model (DPL), Green-Naghdi theory (G-N II, G-N III), coupled theory, and the Lord-Shulman theory (L-S) are employed to solve the present problem. Analytical expressions of the physical quantities are obtained by using Laplace-Fourier transforms technique. Numerical results are shown graphically and the results obtained are analyzed. The most significant points are highlighted.

A novel model of a nonlocal porous thermoelastic solid with temperature-dependent properties using an eigenvalue approach

  • Samia M. Said
    • Geomechanics and Engineering
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    • 제32권2호
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    • pp.137-144
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    • 2023
  • The current article studied wave propagation in a nonlocal porous thermoelastic half-space with temperature-dependent properties. The problem is solved in the context of the Green-Lindsay theory (G-L) and the Lord- Shulman theory (L-S) based on thermoelasticity with memory-dependent derivatives. The governing equations of the porous thermoelastic solid are solved using normal mode analysis with an eigenvalue approach. In order to illustrate the analytical developments, the numerical solution is carried out, and the effect of local parameter and temperature-dependent properties on the physical fields are presented graphically.

Memory response in elasto-thermoelectric spherical cavity

  • El-Attar, Sayed I.;Hendy, Mohamed H.;Ezzat, Magdy A.
    • Coupled systems mechanics
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    • 제9권4호
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    • pp.325-342
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    • 2020
  • A mathematical model of electro-thermoelasticity subjected to memory-dependent derivative (MDD) heat conduction law is applied to a one-dimensional problem of a thermoelectric spherical cavity exposed to a warm stun that is an element of time in the presence of a uniform magnetic field. Utilizing Laplace transform as an instrument, the issue has been fathomed logically within the changed space. Numerical inversion of the Laplace transform is carried for the considered distributions and represented graphically. Some comparisons are shown in the figures to estimate the effects of MDD parameters and thermoelectric properties on the behavior of all considered fields.

Modeling of GN type III with MDD for a thermoelectric solid subjected to a moving heat source

  • Ezzat, Magdy A.
    • Geomechanics and Engineering
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    • 제23권4호
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    • pp.393-403
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    • 2020
  • We design the Green-Naghdi model type III (GN-III) with widespread thermoelasticity for a thermoelectric half space using a memory-dependent derivative rule (MDD). Laplace transformations and state-space techniques are used in order to find the general solution for any set of limit conditions. A basic question of heat shock charging half space and a traction-free surface was added to the formulation in the present situation of a traveling heat source with consistent heating speed and ramp-type heating. The Laplace reverse transformations are numerically recorded. There are called the impacts of several calculations of the figure of the value, heat source spead, MDD parameters, magnetic number and the parameters of the ramping period.

Thermomechanical interactions in a non local thermoelastic model with two temperature and memory dependent derivatives

  • Lata, Parveen;Singh, Sukhveer
    • Coupled systems mechanics
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    • 제9권5호
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    • pp.397-410
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    • 2020
  • The present investigation is concerned with two-dimensional deformation in a homogeneous isotropic non local thermoelastic solid with two temperatures due to thermomechanical sources. The theory of memory dependent derivatives has been used for the study. The bounding surface is subjected to concentrated and distributed sources (mechanical and thermal sources). The Laplace and Fourier transforms have been used for obtaining the solution to the problem in the transformed domain. The analytical expressions for displacement components, stress components and conductive temperature are obtained in the transformed domain. For obtaining the results in the physical domain, numerical inversion technique has been applied. Numerical simulated results have been depicted graphically for explaining the effects of nonlocal parameter on the components of displacements, stresses and conductive temperature. Some special cases have also been deduced from the present study. The results obtained in the investigation should be useful for new material designers, researchers and physicists working in the field of nonlocal material sciences.

A functionally graded magneto-thermoelastic half space with memory-dependent derivatives heat transfer

  • Ezzat, Magdy A.;El-Bary, Alaa A.
    • Steel and Composite Structures
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    • 제25권2호
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    • pp.177-186
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    • 2017
  • In this work, the model of magneto-thermoelasticity based on memory-dependent derivative (MDD) is applied to a one-dimensional thermal shock problem for a functionally graded half-space whose surface is assumed to be traction free and subjected to an arbitrary thermal loading. The $Lam{\acute{e}}^{\prime}s$ modulii are taken as functions of the vertical distance from the surface of thermoelastic perfect conducting medium in the presence of a uniform magnetic field. Laplace transform and the perturbation techniques are used to derive the solution in the Laplace transform domain. A numerical method is employed for the inversion of the Laplace transforms. The effects of the time-delay on the temperature, stress and displacement distribution for different linear forms of Kernel functions are discussed. Numerical results are represented graphically and discussed.