• 제목/요약/키워드: Laplace and Fourier transform

검색결과 64건 처리시간 0.03초

Deformation in a nonlocal magneto-thermoelastic solid with hall current due to normal force

  • Lata, Parveen;Singh, Sukhveer
    • Geomechanics and Engineering
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    • 제22권2호
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    • pp.109-117
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    • 2020
  • The present article is concerned about the study of disturbances in a homogeneous nonlocal magneto-thermoelastic medium under the combined effects of hall current, rotation and two temperatures. The model under assumption has been subjected to normal force. Laplace and Fourier transform have been used for finding the solution to the field equations. The analytical expressions for conductive temperature, stress components, normal current density, transverse current density and displacement components have been obtained in the physical domain using a numerical inversion technique. The effects of hall current and nonlocal parameter on resulting quantities have been depicted graphically. Some particular cases have also been figured out from the current work. The results can be very important for the researchers working in the field of magneto-thermoelastic materials, nonlocal thermoelasticity, geophysics etc.

Effect of hall current in Transversely Isotropic magneto thermoelastic rotating medium with fractional order heat transfer due to normal force

  • Lata, Parveen;Kaur, Iqbal
    • Advances in materials Research
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    • 제7권3호
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    • pp.203-220
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    • 2018
  • This investigation is focused on the study of effect of hall current in transversely isotropic magneto thermoelastic homogeneous medium with fractional order heat transfer and rotation. As an application the bounding surface is subjected to normal force. The research becomes more interesting due to interaction of Hall current with the effect of rotation as it has found various applications. Laplace and Fourier transform is used for solving field equations. The analytical expressions of temperature, displacement components, stress components and current density components are computed in the transformed domain. The effects of hall current and fractional order parameter at different values are represented graphically.

Interactions in a homogeneous isotropic modified couple stress thermoelastic solid with multi-dual-phase-lag heat transfer and two temperature

  • Lata, Parveen;Kaur, Harpreet
    • Steel and Composite Structures
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    • 제38권2호
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    • pp.213-221
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    • 2021
  • The objective of this paper is to study the deformation in a homogeneous isotropic thermoelastic solid using modified couple stress theory subjected to ramp-type thermal source with two temperature. The advantage of this theory is the involvement of only one material length scale parameter which can determine the size effects. Laplace and Fourier transform technique is applied to obtain the solutions of the governing equations. The components of displacement, conductive temperature, stress components and couple stress are obtained in the transformed domain. A numerical inversion technique has been used to obtain the solutions in the physical domain. The effect of two temperature is depicted graphically on the resulted quantities. Numerical results show that the proposed model can capture the size effects of microstructures.

Inclined load effect in an orthotropic magneto-thermoelastic solid with fractional order heat transfer

  • Lata, Parveen;Himanshi, Himanshi
    • Structural Engineering and Mechanics
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    • 제81권5호
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    • pp.529-537
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    • 2022
  • The present research is to study the effect of inclined load in a two-dimensional homogeneous orthotropic magneto-thermoelastic solid without energy dissipation with fractional order heat transfer in generalized thermoelasticity with two-temperature. We obtain the solution to the problem with the help of Laplace and Fourier transformations. The field equations of displacement components, stress components and conductive temperature are computed in transformed domain. Further the results are computed in physical domain by using numerical inversion method. The effect of fractional order parameter and inclined load has been depicted on the resulting quantities with the help of graphs.

Photothermoelastic interactions under Moore-Gibson-Thompson thermoelasticity

  • Kumar, Rajneesh;Sharma, Nidhi;Chopra, Supriya
    • Coupled systems mechanics
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    • 제11권5호
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    • pp.459-483
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    • 2022
  • In the present work, a new photothermoelastic model based on Moore-Gibson-Thompson theory has been constructed. The governing equationsfor orthotropic photothermoelastic plate are simplified for two-dimension model. Laplace and Fourier transforms are employed after converting the system of equations into dimensionless form. The problem is examined due to various specified sources. Moving normal force, ramp type thermal source and carrier density periodic loading are taken to explore the application of the assumed model. Various field quantities like displacements, stresses, temperature distribution and carrier density distribution are obtained in the transformed domain. The problem is validated by numerical computation for a given material and numerical obtained results are depicted in form of graphs to show the impact of varioustheories of thermoelasticity along with impact of moving velocity, ramp type and periodic loading parameters. Some special cases are also explored. The results obtained in this paper can be used to design various semiconductor elements during the coupled thermal, plasma and elastic wave and otherfieldsin thematerialscience, physical engineering.

THE FUNDAMENTAL SOLUTION OF THE SPACE-TIME FRACTIONAL ADVECTION-DISPERSION EQUATION

  • HUANG F.;LIU F.
    • Journal of applied mathematics & informatics
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    • 제18권1_2호
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    • pp.339-350
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    • 2005
  • A space-time fractional advection-dispersion equation (ADE) is a generalization of the classical ADE in which the first-order time derivative is replaced with Caputo derivative of order $\alpha{\in}(0,1]$, and the second-order space derivative is replaced with a Riesz-Feller derivative of order $\beta{\in}0,2]$. We derive the solution of its Cauchy problem in terms of the Green functions and the representations of the Green function by applying its Fourier-Laplace transforms. The Green function also can be interpreted as a spatial probability density function (pdf) evolving in time. We do the same on another kind of space-time fractional advection-dispersion equation whose space and time derivatives both replacing with Caputo derivatives.

THE SPACE-TIME FRACTIONAL DIFFUSION EQUATION WITH CAPUTO DERIVATIVES

  • HUANG F.;LIU F.
    • Journal of applied mathematics & informatics
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    • 제19권1_2호
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    • pp.179-190
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    • 2005
  • We deal with the Cauchy problem for the space-time fractional diffusion equation, which is obtained from standard diffusion equation by replacing the second-order space derivative with a Caputo (or Riemann-Liouville) derivative of order ${\beta}{\in}$ (0, 2] and the first-order time derivative with Caputo derivative of order ${\beta}{\in}$ (0, 1]. The fundamental solution (Green function) for the Cauchy problem is investigated with respect to its scaling and similarity properties, starting from its Fourier-Laplace representation. We derive explicit expression of the Green function. The Green function also can be interpreted as a spatial probability density function evolving in time. We further explain the similarity property by discussing the scale-invariance of the space-time fractional diffusion equation.

Study of two dimensional visco-elastic problems in generalized thermoelastic medium with heat source

  • Baksi, Arup;Roy, Bidyut Kumar;Bera, Rasajit Kumar
    • Structural Engineering and Mechanics
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    • 제29권6호
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    • pp.673-687
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    • 2008
  • In this paper, a thermo-viscoelastic problem in an infinite isotropic medium in two dimensions in the presence of a point heat source is considered. The fundamental equations of the problems of generalized thermoelasticity including heat sources in a thermo-viscoelastic media have been derived in the form of a vector matrix differential equation in the Laplace-Fourier transform domain for a two dimensional problem. These equations have been solved by the eigenvalue approach. The results have been compared to those available in the existing literature. The graphs have been drawn for different cases.

균열이 있는 기능경사 압전 세라믹의 충격 특성에 관한 연구 (Transient Response of Functionally Graded Piezoelectric Ceramic with Crack)

  • Jeong Woo Shin;Tae-Uk Kim;Sung Chan Kim
    • Composites Research
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    • 제16권5호
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    • pp.21-27
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    • 2003
  • 선형 압전 이론(theory of linear piezoelectricity)을 이용하여 면외전단 충격(anti-plane shear impact)을 받는 기능경사 압전 세라믹(functionally graded piezoelectric ceramic)의 중앙에 존재하는 균열(central crack)의 동적 응답에 대해 연구한다. 기능경사 압전재료의 물성치(material property)는 두께방향을 따라 연속적으로 변한다고 가정한다. 라플라스 변환(Laplace transform)과 푸리에 변환(Fourier transform)을 사용하여 두 쌍의 복합적분 방정식을 구성하며, 이를 제2종 Fredholm 적분 방정식(Fredholm integral equations of the second kind)으로 표현한다. 재료 물성치의 변화도(gradient of material properties)와 전기하중(electric loading)의 영향을 보기 위해 동응력세기계수(dynamic stress intensity factor)에 대한 수치 결과를 제시하였다.

A magneto-thermo-viscoelastic problem with fractional order strain under GN-II model

  • Deswal, Sunita;Kalkal, Kapil Kumar;Sheoran, Sandeep Singh
    • Structural Engineering and Mechanics
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    • 제63권1호
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    • pp.89-102
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    • 2017
  • In this work, we present a theoretical framework to study the thermovisco-elastic responses of homogeneous, isotropic and perfectly conducting medium subjected to inclined load. Based on recently developed generalized thermoelasticity theory with fractional order strain, the two-dimensional governing equations are obtained in the context of generalized magnetothermo-viscoelasticity theory without energy dissipation. The Kelvin-Voigt model of linear viscoelasticity is employed to describe the viscoelastic nature of the material. The resulting formulation of the field equations is solved analytically in the Laplace and Fourier transform domain. On the application of inclined load at the surface of half-space, the analytical expressions for the normal displacement, strain, temperature, normal stress and tangential stress are derived in the joint-transformed domain. To restore the fields in physical domain, an appropriate numerical algorithm is used for the inversion of the Laplace and Fourier transforms. Finally, we have demonstrated the effect of magnetic field, viscosity, mechanical relaxation time, fractional order parameter and time on the physical fields in graphical form for copper material. Some special cases have also been deduced from the present investigation.