• Title, Summary, Keyword: Thermoelastic

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Transient Thermoelnstic Analysis of Disk Brakes Using Finite Element Method (유한요소법을 이용한 디스크 브레이크의 과도기 열탄성 해석)

  • Choi, Ji-Hoon;Kim, Do-Hyung;Lee, In;Cha, Hee-Bum;Kang, Min-Gu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.5
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    • pp.160-167
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    • 2002
  • The transient thermoelastic analysis of automotive disk brakes with frictional contact is performed by using the finite element method. To analyze the thermoelastic behaviors occurring in disk brakes, the coupled heat conduction and elastic equations are solved. The fully implicit transient scheme is used to improve the computation accuracy at every time step. The numerical results of the thermoelastic behaviors are obtained during the repeated braking condition. The computational results show that the thermoelastic instability(TEI) phenomenon(the growth of non-uniformities in contact pressure) occurs in disk brakes. Also, the effect of material properties on the thermoelastic behaviors is investigated to facilitate the conceptual design of the brake system.

Finite Element Analysis on the Thermoelastic Wear Behaviors for a High-Speed Disk Brake (고속용 디스크 브레이크의 열탄성 마멸거동에 관한 유한요소해석)

  • 이일권;김청균
    • Tribology and Lubricants
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    • v.15 no.4
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    • pp.291-296
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    • 1999
  • This paper presents the results of thermoelastic wear behaviors in ventilated disk brakes for a high-speed automotive and train using the finite element method. The computed results show that the sinusoidal distortions due to non-uniform distributions of temperature profiles may lead to thermoelastic wears on the rubbing surface. This may decrease the service life of a disk brake and produce micro-cracks, noise and squeals between two rubbing surfaces.

Thermomechanical interactions in transversely isotropic magneto thermoelastic solid with two temperatures and without energy dissipation

  • Lata, Parveen;Kaur, Iqbal
    • Steel and Composite Structures
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    • v.32 no.6
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    • pp.779-793
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    • 2019
  • The purpose of this research paper is to depict the thermomechanical interactions in transversely isotropic magneto thermoelastic solid with two temperatures and without energy dissipation in generalized LS theories of thermoelasticity. The Laplace and Fourier transform techniques have been used to find the solution of 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 numerically. The effect of two temperature and relaxation time are depicted graphically on the resulting quantities.

An lnvestigation of the thermoelastic Behavior in Short Fiber Reinforced Composite Materials (단섬유 보강 복합재료에서의 열탄성 거동에 관한 해석)

  • 김홍건
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.6 no.3
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    • pp.89-95
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    • 1997
  • A simulation to investigate the thermal behavior in short fiber or whisker reinforced composite materials has been performed for the application to the thermoelastic stress analysis using Finite Element Method (FEM). To obtain the internal field quantities of composite material, the procedure of micromechanical modeling and the principle of virtual work were implemented. For the numerical illustration, an aligned axisymmetric single fiber model has been employed to assess field quantities. It was found that the proposed simulation methodology for thermoelastic stress analysis is applicable to the complicated inhomogeneous solid for the investigation of micromechanical thermoelastic behavior.

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Effects of stiffness on reflection and transmission of micropolar thermoelastic waves at the interface between an elastic and micropolar generalized thermoelastic solid

  • Kumar, Rajneesh;Sharma, Nidhi;Ram, Paras
    • Structural Engineering and Mechanics
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    • v.31 no.2
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    • pp.117-135
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    • 2009
  • The reflection and transmission of micropolar thermoelastic plane waves at the interface between an elastic solid and micropolar generalized thermoelastic solid is discussed. The interface boundary conditions obtained contain interface stiffness (normal stiffness and transverse stiffness). The expressions for the reflection and transmission coefficients which are the ratios of the amplitudes of reflected and transmitted waves to the amplitude of incident waves are obtained for normal force stiffness, transverse force stiffness and welded contact. Numerical calculations have been performed for amplitude ratios of various reflected and transmitted waves. The variations of amplitude ratios with angle of incident wave have been depicted graphically. It is found that the amplitude ratios of reflected and transmitted waves are affected by the stiffness, micropolarity and thermal distribution of the media.

TRANSIENT THERMOELASTIC STRESS ANALYSIS OF A THIN CIRCULAR PLATE DUE TO UNIFORM INTERNAL HEAT GENERATION

  • GAIKWAD, KISHOR R.;NANER, YOGESH U.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.24 no.3
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    • pp.293-303
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    • 2020
  • The present work aims to analyzed the transient thermoelastic stress analysis of a thin circular plate with uniform internal heat generation. Initially, the plate is characterized by a parabolic temperature distribution along the z-direction given by T = T0(r, z) and perfectly insulated at the ends z = 0 and z = h. For times t > 0, the surface r = a is subjected to convection heat transfer with convection coefficient hc and fluid temperature T. The integral transform method used to obtain the analytical solution for temperature, displacement, and thermal stresses. The associated thermoelastic field is analyzed by making use of the temperature and thermoelastic displacement potential function. Numerical results are carried out with the help of computational software PTC Mathcad Prime-3.1 and shown in figures.

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.

Thermoelastic deformation and stress analysis of a FGM rectangular Plate (경사기능재료 사각 판의 열 탄성 변형과 응력 해석)

  • Kim,Gwi-Seop
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.1
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    • pp.34-41
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    • 2003
  • A Green's function approach is adopted for analyzing the thermoelastic deformation and stress analysis of a plate made of functionally graded materials (FGMs). The solution to the 3-dimensional steady temperature is obtained by using the laminate theory. The fundamental equations for thermoelastic problems are derived in terms of out-plane deformation and in-plane force, separately. The thermoelastic deformation and the stress distributions due to the bending and in-plane forces are analyzed by using a Green’Às function based on the Galerkin method. The eigenfunctions of the Galerkin Green's function for the thermoelastic deformation and the stress distributions are approximated in terms of a series of admissible functions that satisfy the homogeneous boundary conditions of the rectangular plate. Numerical examples are carried out and effects of material properties on thermoelastic behaviors are discussed.

Thermoelastic effect on inter-laminar embedded delamination characteristics in Spar Wingskin Joints made with laminated FRP composites

  • Mishra, P.K.;Pradhan, A.K.;Pandit, M.K.;Panda, S.K.
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.439-447
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    • 2020
  • This paper presents two sets of full three-dimensional thermoelastic finite element analyses of superimposed thermo-mechanically loaded Spar Wingskin Joints made with laminated Graphite Fiber Reinforced Plastic composites. The study emphasizes the influence of residual thermal stresses and material anisotropy on the inter-laminar delamination behavior of the joint structure. The delamination has been pre-embedded at the most likely location, i.e., in resin layer between the top and next ply of the fiber reinforced plastic laminated wingskin and near the spar overlap end. Multi-Point Constraint finite elements have been made use of at the vicinity of the delamination fronts. This helps in simulating the growth of the embedded delamination at both ends. The inter-laminar thermoelastic peel and shear stresses responsible for causing delamination damage due to a combined thermal and a static loading have been evaluated. Strain energy release rate components corresponding to the Mode I (opening), Mode II (sliding) and Mode III (tearing) of delamination are determined using the principle of Virtual Crack Closure Technique. These are seen to be different and non-self-similar at the two fronts of the embedded delamination. Residual stresses developed due to the thermoelastic anisotropy of the laminae are found to strongly influence the delamination onset and propagation characteristics, which have been reflected by the asymmetries in the nature of energy release rate plots and their significant variation along the delamination front.

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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    • 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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