• Title/Summary/Keyword: Uniform Deformation Theory

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Thermal postbuckling of imperfect Reissner-Mindlin plates with two free side edges and resting on elastic foundations

  • Shen, Hui-Shen
    • Structural Engineering and Mechanics
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    • v.6 no.6
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    • pp.643-658
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    • 1998
  • A thermal postbuckling analysis is presented for a moderately thick rectangular plate subjected to uniform or nonuniform tent-like temperature loading and resting on an elastic foundation. The plate is assumed to be simply supported on its two opposite edges and the two side edges remain free. The initial geometrical imperfection of the plate is taken into account. The formulation are based on the Reissner-Mindlin plate theory considering the first order shear deformation effect, and including plate-foundation interaction and thermal effects. The analysis uses a mixed Galerkin-perturbation technique to determine the thermal buckling loads and postbuckling equilibrium paths. Numerical examples are presented that relate to the performances of perfect and imperfect, moderately thick plates resting on Pasternak-type or softening nonlinear elastic foundations from which results for Winker elastic foundations follow as a limiting case. Typical results are presented in dimensionless graphical form.

Thermomechanical postbuckling of imperfect moderately thick plates on two-parameter elastic foundations

  • Shen, Hui-Shen
    • Structural Engineering and Mechanics
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    • v.4 no.2
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    • pp.149-162
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    • 1996
  • A postbuckling analysis is presented for a simply supported, moderately thick rectangular plate subjected to combined axial compression and uniform temperature loading and resting on a two-parameter elastic foundation. The two cases of thermal postbuckling of initially compressed plates and of compressive postbuckling of initially heated plates are considered. The initial geometrical imperfection of the plate is taken into account. The formulations are based on the Reissner-Mindlin plate theory considering the first order shear deformation effect, and including the plate-foundation interaction and thermal effect. The analysis uses a deflection-type perturbation technique to determine the buckling loads and postbuckling equilibrium paths. Numerical examples cover the performances of perfect and imperfect, moderately thick plates resting on Winkler or Pasternak-type elastic foundations. Typical results are presented in dimensionless graphical form.

Spectral Element Modeling of Rotating Shafts by Using Variational Method (변분법을 이용한 회전축의 스펙트럴요소 모델링)

  • Yong, Suk-Jin;Lee, Jae-Sng;Lee, U-Sik
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.923-926
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    • 2007
  • In this paper, the vibration of a rotating shaft with a thin rigid disk is considered. It is assumed that the shaft has uniform, circular cross-section. Based on the Timoshenko-beam theory, the transverse displacements and slops in two lateral directions, the axial displacement, and the torsional deformation are considered. A spectral element model is developed by using the variation method for the vibration analysis of the rotating shaft with a thin rigid disk, which is modeled by two shaft elements and a thin rigid disk element. The result of vibration analysis by finite element method is compared to the result of this research.

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Free Vibrations of Cylindrical Shells on Inclined Partial Elastic Foundation (경사진 부분 탄성 지지부를 갖는 원통셸의 자유진동)

  • Park, Kyung-Jo;Kim, Young-Wann
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.3
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    • pp.261-267
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    • 2014
  • The free vibration characteristics of cylindrical shells on inclined partial elastic foundations are investigated by an analytical method. The cylindrical shell is partially surrounded by the elastic foundations, these are represented by the Winkler or Pasternak model. The area of elastic foundation is not uniform and varies along the axial direction of the shell. The motion of shell is represented by first-order shear deformation theory(FSDT) to account for rotary inertia and transverse shear strains. The governing equation is obtained using the Rayleigh-Ritz method and a variation approach. To validate the present method, the numerical example is presented and compared with the present FEA results. The numerical results reveal that the elastic foundation has significant effect on vibration characteristics.

Stochastic bending characteristics of finite element modeled Nano-composite plates

  • Chavan, Shivaji G.;Lal, Achchhe
    • Steel and Composite Structures
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    • v.26 no.1
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    • pp.1-15
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    • 2018
  • This study reported, the effect of random variation in system properties on bending response of single wall carbon nanotube reinforced composite (SWCNTRC) plates subjected to transverse uniform loading is examined. System parameters such as the SWCNT armchair, material properties, plate thickness and volume fraction of SWCNT are modelled as basic random variables. The basic formulation is based on higher order shear deformation theory to model the system behaviour of the SWCNTRC composite plate. A C0 finite element method in conjunction with the first order perturbation technique procedure developed earlier by the authors for the plate subjected to lateral loading is employed to obtain the mean and variance of the transverse deflection of the plate. The performance of the stochastic SWCNTRC composite model is demonstrated through a comparison of mean transverse central deflection with those results available in the literature and standard deviation of the deflection with an independent First Order perturbation Technique (FOPT), Second Order perturbation Technique (SOPT) and Monte Carlo simulation.

Deformation of a rectangular plate with an arbitrarily located circular hole under in-plane pure shear loading

  • Yang, Yeong-Bin;Kang, Jae-Hoon
    • Structural Engineering and Mechanics
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    • v.60 no.2
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    • pp.351-363
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    • 2016
  • Exact solutions for stresses, strains, displacements, and the stress concentration factors of a rectangular plate perforated by an arbitrarily located circular hole subjected to in-plane pure shear loading are investigated by two-dimensional theory of elasticity using the Airy stress function. The hoop stresses, strains, and displacements occurring at the edge of the circular hole are computed and plotted. Comparisons are made for the hoop stresses and the stress concentration factors from the present study and those from a rectangular plate with a circular hole under uni-axial and bi-axial uniform tensions and in-plane pure bending moments on two opposite edges.

Spectral Element Modeling of the Rotating Shafts on Bearing Supports (베어링으로 지지된 회전축의 스펙트럴요소 모델링)

  • Lee, Jae-Sng;Lee, U-Sik
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.826-830
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    • 2008
  • In this paper, the vibration of a rotating shaft with a thin rigid disk on bearing supports is considered. It is assumed that the shaft has uniform, circular cross-section. Based on the Timoshenko-beam theory, the transverse displacements and slops in two lateral directions, the axial displacement, and the torsional deformation are considered. And flexible supports are used to analyse the bearings. A spectral element model is developed for the vibration analysis of the rotating shaft with a thin rigid disk, which is modeled by two shaft elements and a thin rigid disk element. The result of vibration analysis by finite element method is compared to the result of this research.

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Thermo-elastic stability behavior of laminated cross-ply elliptical shells

  • Patel, B.P.;Shukla, K.K.;Nath, Y.
    • Structural Engineering and Mechanics
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    • v.19 no.6
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    • pp.749-755
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    • 2005
  • In this work, thermo-elastic stability behavior of laminated cross-ply elliptical cylindrical shells subjected to uniform temperature rise is studied employing the finite element approach based on higher-order theory that accounts for the transverse shear and transverse normal deformations, and nonlinear in-plane displacement approximations through the thickness with slope discontinuity at the layer interfaces. The combined influence of higher-order shear deformation, shell geometry and non-circularity on the prebuckling thermal stress distribution and critical temperature parameter of laminated elliptical cylindrical shells is examined.

Effect of laminate configuration on the free vibration/buckling of FG Graphene/PMMA composites

  • Zeverdejani, Mehran Karimi;Beni, Yaghoub Tadi
    • Advances in nano research
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    • v.8 no.2
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    • pp.103-114
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    • 2020
  • In this research, buckling and free vibration of rectangular polymeric laminate reinforced by graphene sheets are investigated. Various patterns are considered for augmentation of each laminate. Critical buckling load is evaluated for different parameters, including boundary conditions, reinforcement pattern, loading regime, and laminate geometric states. Furthermore, vibration analysis is investigated for square laminate. Elastic properties of the composite are calculated using a combination of both molecular dynamics (MD) and the rule of mixture (MR). Kinematics of the plate is approximated based on the first shear deformation theory (FSDT). The current analysis is performed based on the energy method. For the numerical investigation, Ritz method is applied, and for shape functions, Chebyshev polynomials are utilized. It is found that the number of layers is effective on the buckling load and natural frequency of laminates which made from non-uniform layers.

Effect of inclined load on transversely isotropic magneto thermoelastic rotating solid with time harmonic source

  • Lata, Parveen;Kaur, Iqbal
    • Advances in materials Research
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    • v.8 no.2
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    • pp.83-102
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    • 2019
  • The present research deals with the time harmonic deformation in transversely isotropic magneto thermoelastic solid with two temperature (2T), rotation and without energy dissipation due to inclined load. Lord-Shulman theory has been formulated for this mathematical model. The entire thermo-elastic medium is rotating with a uniform angular velocity. 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 time harmonic source and rotation is depicted graphically on the resulting quantities.