• Title/Summary/Keyword: Transversely isotropic

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Dynamic analysis of a transversely isotropic non-classical thin plate

  • Fadodun, Odunayo O.;Borokinni, Adebowale S.;Layeni, Olawanle P.;Akinola, Adegbola P.
    • Wind and Structures
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    • v.25 no.1
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    • pp.25-38
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    • 2017
  • This study investigates the dynamic analysis of a transversely isotropic thin plate. The plate is made of hyperelastic John's material and its constitutive law is obtained by taken the Frechect derivative of the highlighted energy function with respect to the geometry of deformation. The three-dimensional equation governing the motion of the plate is expressed in terms of first Piola-Kirchhoff's stress tensor. In the reduction to an equivalent two-dimensional plate equation, the obtained model generalizes the classical plate equation of motion. It is obtained that the plate under consideration exhibits harmonic force within its planes whereas this force varnishes in the classical plate model. The presence of harmonic forces within the planes of the considered plate increases the natural and resonance frequencies of the plate in free and forced vibrations respectively. Further, the parameter characterizing the transversely isotropic structure of the plate is observed to increase the plate flexural rigidity which in turn increases both the natural and resonance frequencies. Finally, this study reinforces the view that non-classical models of problems in elasticity provide ample opportunity to reveal important phenomena which classical models often fail to apprehend.

A Study on the Development of Photoelastic Experiment Model Material for Transversely Isotropic Material (횡등방성체용 광탄성재료 개발에 관한 연구)

  • 황재석;김병일;이광호;최선호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.1876-1888
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    • 1995
  • In this paper, glass surface-mat reinforced epoxy(G.S.R.E.) is developed, It is assured that the material(G.S.R.E.) can be used as photoelastic model material and it satisfy with the required properties of photoelastic model material. Therefore, the material can be used as model material of transparent photoelastic experiment when we analyze the stress distributions of transversely isotropic material by photoelastic experiment. When we use G.S.R.E. as photoelastic experiment model material, we had better use the G.S.R.E. which fiber volume ratio is less than 0.7% in the high temperature(stress freezing method) and than 1.74% in the room temperature. Relationships between stress fringe value and elastic modulus in transversely isotropic material are developed in this paper, it is assured by experiment that they are established in the room temperature or in the high temperature. Therefore we can obtain stress fringe value or elastic modulus from the relationships between stress fringe value and elastic modulus.

An Investigation of Anisotropic Tensile Strength of Transversely Isotropic Rock by Critical Plane Approach (임계면법을 이용한 횡등방성 암석의 이방성 인장강도 해석)

  • Lee, Youn-Kyou
    • Tunnel and Underground Space
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    • v.18 no.3
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    • pp.194-201
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    • 2008
  • In order to investigate the characteristics in tensile strength of transversely isotropic rock, a new anisotropic tensile failure function was suggested. According to the function, the tensile strength is minimum in the normal direction to a weakness plane and rises exponentially to its maximum on a plane perpendicular to the weakness plane. The anisotropic function is defined in terms of three strength parameters which can be identified trom direct tensile tests of transversely isotropic rocks. By incorporating the suggested function into the critical plane approach, a numerical procedure which enables to search the tensile strength and the direction of critical plane at failure was presented. The validity of the suggested numerical procedure was checked through the simulation of direct tensile tests reported in a literature. The numerical results from the simulation were in good agreements with those from the laboratory tests.

AN ENERGY FUNCTION FOR TRANSVERSELY-ISOTROPIC ELASTIC MATERIAL AND THE PONYTING EFFECT

  • Akinola, Ade
    • Journal of applied mathematics & informatics
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    • v.6 no.3
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    • pp.873-884
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    • 1999
  • On the basis of the semi-linear material of John invoking the theory of homogenization for heterogeneous media and the theory of invariants for isotropic scalar functions an energy function is built for a transversely-isotropic medium in finite elastic deformation. The ponyting Effect for material in simple shear is reviewed for this case of transversal isotropy. It is shown that this effect is apprehended by the constructed energy function.

Anisotropic Analysis of Tunnel in Transversely Isotropic Rock (횡등방성 암반 내 터널의 이방성 해석)

  • Choi Mi-Jin;Yang Hyung-Sik
    • Tunnel and Underground Space
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    • v.15 no.6 s.59
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    • pp.391-399
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    • 2005
  • In this study, stress difference between isotropic and transversely isotropic rock mass, and planar principal stresses at the periphery of the tunnel in the rock with various ratio of anisotropy were determined theoretically. Stress differences between isotropic and anisotropic calculations at crown. side walls and floor of a tunnel with assumed stress states were analyzed and compare each other by $FLAC^{2D}$, a finite differential element method. As a result, magnitude and direction of principal stresses in the case of ignoring anisotropy were different from those of anisotropic cases, whatever the stress state was. Stress difference increased as the ratio of anisotropy increased. Direction or anisotropy affected stress difference, especially in the cases of anisotropic directions of $45^{\circ}\;and\;135^{\circ}$ of counterclockwise from x direction.

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.

Stability analysis of transversely isotropic laminated Mindlin plates with piezoelectric layers using a Levy-type solution

  • Ghasemabadian, M.A.;Saidi, A.R.
    • Structural Engineering and Mechanics
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    • v.62 no.6
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    • pp.675-693
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    • 2017
  • In this paper, based on the first-order shear deformation plate theory, buckling analysis of piezoelectric coupled transversely isotropic rectangular plates is investigated. By assuming the transverse distribution of electric potential to be a combination of a parabolic and a linear function of thickness coordinate, the equilibrium equations for buckling analysis of plate with surface bonded piezoelectric layers are established. The Maxwell's equation and all boundary conditions including the conditions on the top and bottom surfaces of the plate for closed and open circuited are satisfied. The analytical solution is obtained for Levy type of boundary conditions. The accurate buckling load of laminated plate is presented for both open and closed circuit conditions. From the numerical results it is found that, the critical buckling load for open circuit is more than that of closed circuit in all boundary and loading conditions. Furthermore, the critical buckling loads and the buckling mode number increase by increasing the thickness of piezoelectric layers for both open and closed circuit conditions.

Axisymmetric deformation in transversely isotropic thermoelastic medium using new modified couple stress theory

  • Lata, Parveen;Kaur, Harpreet
    • Coupled systems mechanics
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    • v.8 no.6
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    • pp.501-522
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    • 2019
  • The present study is concerned with the thermoelastic interactions in a two dimensional axisymmetric problem in transversely isotropic thermoelastic solid using new modified couple stress theory without energy dissipation and with two temperatures. The Laplace and Hankel transforms have been employed to find the general solution to the field equations. Concentrated normal force, normal force over the circular region, concentrated thermal source and thermal source over the circular region have been taken to illustrate the application of the approach. The components of displacements, stress, couple stress and conductive temperature distribution are obtained in the transformed domain. The resulting quantities are obtained in the physical domain by using numerical inversion technique. The effect of two temperature varying by taking different values for the two temperature on the components of normal stress, tangential stress, conductive temperature and couple stress are depicted graphically.

Propagation of plane wave in transversely isotropic magneto-thermoelastic material with multi-dual-phase lag and two temperature

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Coupled systems mechanics
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    • v.9 no.5
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    • pp.411-432
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    • 2020
  • This research is devoted to the study of plane wave propagation in homogeneous transversely isotropic (HTI) magneto-thermoelastic rotating medium with combined effect of Hall current and two temperature due to multi-dual-phase lag heat transfer. It is analysed that, for 2-D assumed model, three types of coupled longitudinal waves (quasi-longitudinal, quasi-transverse and quasi-thermal) are present. The wave characteristics like phase velocity, specific loss, attenuation coefficients, energy ratios, penetration depths and amplitude ratios of transmitted and reflected waves are computed numerically and illustrated graphically and compared for different theories of thermoelasticity. Some particular cases are also derived from this research.

Transversely isotropic thin circular plate with multi-dual-phase lag heat transfer

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.343-351
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    • 2020
  • The present research deals with the multi-dual-phase-lags thermoelasticity theory for thermoelastic behavior of transversely isotropic thermoelastic thin circular plate The Laplace and Hankel transform techniques have been used to find the solution of the problem. The displacement components, stress components, and conductive temperature distribution are computed in the transformed domain with the radial distance and further determined in the physical domain using numerical inversion techniques. The effect of rotation and two temperature are depicted graphically on the resulting quantities.