• 제목/요약/키워드: anisotropic plate

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Assessment of Equivalent Elastic Modulus of Perforated Spherical Plates

  • JUMA, Collins;NAMGUNG, Ihn
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.15 no.1
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    • pp.8-17
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    • 2019
  • Perforated plates are used for the steam generator tube-sheet and the Reactor Vessel Closure Head in the Nuclear Power Plant. The ASME code, Section III Appendix A-8000, addresses the analysis of perforated plates, however, this analysis is only limited to the flat plate with a triangular perforation pattern. Based on the concept of the effective elastic constants, simulation of flat and spherical perforated plates and their equivalent solid plates were carried out using Finite Element Analysis (FEA). The isotropic material properties of the perforated plate were replaced with anisotropic material properties of the equivalent solid plate and subjected to the same loading conditions. The generated curves of effective elastic constants vs ligament efficiency for the flat perforated plate were in agreement with the design curve provided by ASME code. With this result, a plate with spherical curvature having perforations can be conveniently analyzed with equivalent elastic modulus and equivalent Poisson's ratio.

Thermal buckling analysis of thick anisotropic composite plates by finite strip method

  • Cheung, M.S.;Akhras, G.;Li, W.
    • Structural Engineering and Mechanics
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    • v.7 no.5
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    • pp.473-484
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    • 1999
  • In the present study, the thermal buckling analysis of thick anisotropic laminated composite plates is carried out using the finite strip method based on the higher-order shear deformation theory. This theory accounts for the parabolic distribution of the transverse shear strains through the thickness of the plate and for zero transverse shear stresses on the plate surfaces. Therefore, this theory yields improved results over the Mindlin plate theory and eliminates the need for shear correction factors in calculating the transverse shear stiffness. The critical temperatures of simply supported rectangular cross-ply and angle-ply composite laminates are calculated. The effects of several parameters, such as the aspect ratio, the length-to-thickness ratio, the number of plies, fibre orientation and stacking sequence, are investigated.

Investigation of wave propagation in anisotropic plates via quasi 3D HSDT

  • Bouanati, Soumia;Benrahou, Kouider Halim;Atmane, Hassen Ait;Yahia, Sihame Ait;Bernard, Fabrice;Tounsi, Abdelouahed;Bedia, E.A. Adda
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.85-96
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    • 2019
  • A free vibration analysis and wave propagation of triclinic and orthotropic plate has been presented in this work using an efficient quasi 3D shear deformation theory. The novelty of this paper is to introducing this theory to minimize the number of unknowns which is three; instead four in other researches, to studying bulk waves in anisotropic plates, other than it can model plates with great thickness ratio, also. Another advantage of this theory is to permits us to show the effect of both bending and shear components and this is carried out by dividing the transverse displacement into the bending and shear parts. Hamilton's equations are a very potent formulation of the equations of analytic mechanics; it is used for the development of wave propagation equations in the anisotropic plates. The analytical dispersion relationship of this type of plate is obtained by solving an eigenvalue problem. The accuracy of the present model is verified by confronting our results with those available in open literature for anisotropic plates. Moreover Numerical examples are given to show the effects of wave number and thickness on free vibration and wave propagation in anisotropic plates.

Mixed Mode Analysis of Bonded Anisotropic Structures With a Crack (크랙 이 있는 異方性 接着構造物 의 혼합모우드 解析)

  • 홍창선;정광영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.2
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    • pp.145-152
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    • 1983
  • An adhesively bonded anisotropic structure containing a part-through crack subjected to in-plane mixed mode deformations is investigated. The problem is reduced to a pair of Fredholm integral equations of the second kind by mathematical analysis. By solving these equations numerically stress intensity factors k$_{1}$ and k$_{2}$ are presented. Two cases are considered with respect to fiber orientations. Case one is to fix the fiber orientations of sound plate bonded to cracked plate with various fiber orientations. The other is to vary fiber orientations for both plates. As boundary conditions, tension and shear loading respectively, are applied to bonded anisotropic plates to observe mixed mode deformations.

Buckling Analysis of Anisotropic Laminated Plates with Shear Deformation (전단변형을 고려한 이방성 적층판의 좌굴해석)

  • 최용희;권택진
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.361-368
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    • 2001
  • This paper deals with the buckling load of antisymmetric angle-ply and cross-ply laminated rectangular plates. Buckling analysis is preformed for a simply supported, shear deformable laminated plate subjected to uniaxial compression and biaxial compression combined with uniform lateral pression. The shear deformation theory is considered to figure out a more exact behavior of laminated plates exactly. The purposes of this study are to formulate anisotropic laminated plates with shear deformation and to investigate the buckling load according to the various variables of laminated plates by using the exact solutions for anisotropic laminated plates having simply supported boundary.

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A Study on the Failure Characteristics of Equivalent Anisotropic Composite Plates (등가 이방성 복합재 평판에 대한 파손 특성에 관한 연구)

  • Yun, Jaeho;Kim, Hanjun;Kim, Yongha
    • Journal of Aerospace System Engineering
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    • v.16 no.5
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    • pp.35-42
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    • 2022
  • This paper deals with predicting comparable mechanical properties of laminated composite plates. The stiffness of an equivalent anisotropic composite plate is derived based on classical lamination theory. A novel failure criterion is defined to describe the failure behaviour of laminated composite plates based on micro-mechanics failure criteria. Finally, the theory's validation of finite element analysis results was verified. We concluded that this theory is very suitable for failure analysis of laminated composite plates for aerospace applications due to their relative simplicity and computational efficiency.

On exact wave propagation analysis of triclinic material using three-dimensional bi-Helmholtz gradient plate model

  • Karami, Behrouz;Janghorban, Maziar;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.69 no.5
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    • pp.487-497
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    • 2019
  • Rapid advances in the engineering applications can bring further areas to provide the opportunity to manipulate anisotropic structures for direct productivity in design of micro/nano-structures. For the first time, magnetic affected wave characteristics of nanosize plates made of anisotropic material is investigated via the three-dimensional bi-Helmholtz nonlocal strain gradient theory. Three small scale parameters are used to predict the size-dependent behavior of the nanoplates more accurately. After owing governing equations of wave motion, an analytical approach based harmonic series is utilized to fine the wave frequency as well as phase velocity. It is observed that the small scale parameters, magnetic field and wave number have considerable influence on the wave characteristics of anisotropic nanoplates. Due to the lack of any study on the mechanics of three-dimensional bi-Helmholtz gradient plates made of anisotropic materials, it is hoped that the present exact model may be used as a benchmark for future works of such nanostructures.

A Study on the Characteristics of Elastic Wave Propagation in Plates Using Pulse Laser Holographic Interferometry (펄스 레이저 홀로그래픽 간섭계를 이용한 평판의 탄성파 전파 특성에 관한 연구)

  • 이기백;나종문;김정훈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.04a
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    • pp.106-112
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    • 1996
  • In this paper, the propagation of elastic wave generated by loading impact to plates made of isotropic or anisotropic material was studied. And the influence of boundary conditions(free or clamped edge) upon the reflection of elastic wave of isotropic plate such as aluminum plate showed circular interferometric fringe pattern, whereas that of anisotropic plate such as epoxy composite laminates showed elliptical one. And the transverse displacement curves obtained from experiment and theory for both plates agreed well. Also, the waves reflected from the boundary edges showed much differences according to the boundary condition of edges.

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A Study on the Characteristics of Elastic Wave Propagation in Plates Using Double Pulsed Laser Holographic Interferometry (이중펄스레이저 홀로그래픽 간섭법을 이용한 평판의 탄성파 전파특성에 관한 연구)

  • Lee, Ki-Baik;Na, Jong-Moon;Kim, Jeong-Hun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.10
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    • pp.3211-3223
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    • 1996
  • In this paper, the propagation of elastic wave generated by loading impact to plates made of isotropic of anisotropic material was studied. And the influence of boundary conditions (free or clamped edge) upon the reflection of elastic wave was anlyzed. Also, double exposure holographic interferometer using ruby pulse laser was formed in order to investigate transient waves. Before the elasitc wave was reflected from the edges, the elastic wave of isotropic plate such as aluminum plate showed circular interferometric fringe pattern, whereas that of anisotropic plate such as epoxy composite laminates showed elliptical one. And the transverse displacement curves obtained from experiment and theory for both plates agreed well. Also, the waves reflected from the boundary edges showed much differences according to the boundary condition of edges.

Polarized Light Out-coupling in Backlight by Collimating the Beam into Lightguide Plate

  • Hwang, Seong-Mo;Kim, Yeun-Tae;Nam, Seung-Ho;Lee, Sin-Doo
    • Journal of Information Display
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    • v.8 no.1
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    • pp.18-21
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    • 2007
  • We developed a new configuration of polarized light out-coupling lightguide plate (LGP) in the LCD backlight. By collimating the light into the LGP, one linear polarization component experienced total internal reflection at the planar interface of LGP and anisotropic layer, whereas the orthogonal polarization was out-coupled along the normal direction through a birefringent layer and subsequent isotropic microstructures.