• Title/Summary/Keyword: Specially Orthotropic

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Simple Method of Analysis for Concrete Slab Bridges by the Specially Orthotropic Laminates Theory (특별직교이방성 적층판이론에 의한 콘크리트 슬래브교량의 간편해석법)

  • Han, Bong-Koo;Suck, Jun-Ho
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.1 no.2
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    • pp.59-65
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    • 2010
  • The simple supported reinforced concrete slab bridges are analyzed by the specially orthotropic laminates theory. This method, however, may be too difficult for some practising engineers. In this paper, the result of analysis for such plate by means of the beam theory with unit width is reported. By using the "correction factor", the accurate solution for the plate can be obtained by the beam theory. By using the "correction factor", the accurate solution for the plate can be obtained by the beam theory. The plate aspect ratio considered is from 1 : 1 to 1 : 6. The result of this paper can be used for simply supported slab bridges analysis.

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A Study on Size/Scale Effects in the Failure of Specially Orthotropic Slab Bridges (특별직교이방성 슬래브 교량의 파괴시 치수효과에 관한 연구)

  • Han, Bong-Koo;Kim, Duck-Hyun
    • Composites Research
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    • v.23 no.1
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    • pp.23-30
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    • 2010
  • Most of the bridge systems, including the girders, cross-beams, and concrete decks behave as specially orthotropic plates. In general, the analytical solution for such complex system is very difficult to obtain. In this paper presented, a design method of slab bridge of simple supported made by composite materials. For the design of bridge made by the composite materials, cross-section was used the form-core shape because of this shape is economical and profitable, and for output of the stress value used finite difference method. In this paper, the rate of tensile strength reduction due to increased size was considered. Strength-failure analysis procedure, using the reduced tensile strength, was presented. And also numerical study was made for these cases.

A Simple and Accurate Analysis of Two Dimensional Concrete Slab for a Railroad Bridge by the Composite Laminates Plate Theory (복합적층판 이론에 의한 2차원 콘크리트 슬래브 철도교량의 정확하고 간단한 해석)

  • Han, Bong-Koo;Bang, Bae-San
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.2 no.2
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    • pp.20-25
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    • 2011
  • In this paper, two dimensional concrete slabs for a railroad bridge were analyzed by the specially orthotropic laminates theory. Both the geometrical and material property of the cross section of the slab was considered symmetrically with respect to the neutral surface so that the bending extension coupling stiffness, $B_{ij}$ = 0, and $D_{16}=D_{26}=0$ Bridge deck behaves as specially orthotropic plates. In general, the analytical solution for such complex systems is very difficult to obtain. Thus, finite difference method was used for analysis of the problem. In this paper, the finite difference method and the beam theory were used for analysis.

A Study on Post-Tensioned Reinforced Concrete Slab by the Beam Theory (포스트텐션된 철근콘크리트 슬래브의 보 이론에 의한 연구)

  • Han, Bong-Koo;Kim, Duck-Hyun
    • Composites Research
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    • v.22 no.5
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    • pp.24-29
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    • 2009
  • In this paper, a post-tensioned reinforced concrete slab was analyzed by the specially orthotropic laminates theory. Both the geometrical and material property of the cross section of the slab was considered symmetrically with respect to the neutral surface so that the bending extension coupling stiffness, $B_{ij}=0$, and $D_{16}=D_{26}=0$. Reinforced concrete slab behave as specially orthotropic plates. In general, the analytical solution for such complex systems is very difficult to obtain. Thus, finite difference method was used for analysis of the problem. In this paper, the finite difference method and the beam theory were used for analysis. The result of beam analysis was modified to obtain the solution of the plate analysis.

Stress analysis for the orthotropic cylindrical shells subjected to line load based on Novozhilov's shell theory (선하중을 받는 직교이방성 원통셀의 Novozhilov셀 이론에 의한 응력해석)

  • 이영신;최병두
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.5
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    • pp.789-799
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    • 1987
  • The stress state and displacement for the orthotropic cylindrical shell subjected to line load along a generator is presented. It is assumed that the behavior of the material is specially-orthotropic. The governing equation for orthotropic cylindrical shell is derived on the basis of Novozhilov's shell theory. General solution is obtained by extending the Naghdi's method for the isotropic cylindrical shell under the line load. Numerical examples are presented for circular cylindrical shells having various othotropic material properties and geometries.

Free vibration analysis of elliptic and circular plates having rectangular orthotropy

  • Chakraverty, S.;Petyt, M.
    • Structural Engineering and Mechanics
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    • v.7 no.1
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    • pp.53-67
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    • 1999
  • The natural frequencies and modes of free vibration of specially orthotropic elliptic and circular plates are analysed using the Rayleigh-Ritz method. The assumed functions used are two-dimensional boundary characteristic orthogonal polynomials which are generated using the Gram-Schmidt orthogonalization procedure. The first five natural frequencies are reported here for various values of aspect ratio of the ellipse. Results are given for various boundary conditions at the edges i.e., the boundary may be any of clamped, simply-supported or fret. Numerical results are presented here for several orthotropic material properties. For rectilinear orthotropic circular plates, a few results are available in the existing literature, which are compared with the present results and are found to be in good agreement.

The Influence of the Aspect Ratio on the Composite Material Bridge Deck Structures

  • Han, Bong-Koo
    • Composites Research
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    • v.27 no.1
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    • pp.1-6
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    • 2014
  • Theories for composite material structures are too difficult for such design engineers for construction and some simple but accurate enough methods are necessary. The author has reported that some laminate orientations have decreasing values of $D_{16}$, $B_{16}$, $D_{26}$ and $B_{26}$ stiffnesses as the ply number increases. For such plates, the fiber orientations given above behave as specially orthotropic plates and simple formulas developed by the author. Most of the bridge deck structures on girders have large aspect ratios. For such cases further simplification is possible by neglecting the effect of the longitudinal moment terms $M_x$ on the relevant partial differential equations of equilibrium. In this paper, the result of the study on the subject problem is presented.

Analysis of Prestressed Concrete Slab Bridge by the Beam Theory (보 이론에 의한 PSC 슬래브 교량의 해석)

  • Han, Bong-Koo;Kim, Duk-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.2
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    • pp.115-124
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    • 2003
  • A prestressed concrete slab bridge is analyzed by the specially orthotropic laminates theory. Both the geometry and the material of the cross section of the slab are considered symmetrical with respect to the mid-surface so that the bending extension coupling stiffness, $B_{ij}=0$, and $D_{16}=D_{26}=0$. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This bridge with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and the beam theory are used for analysis. The result of beam analysis is modified to obtain the solution of the plate analysis.

An investigation into the mechanics of fiber reinforced composite disk springs

  • Yang, Peng;Van Dyke, Stacy;Elhajjar, Rani F.
    • Steel and Composite Structures
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    • v.18 no.3
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    • pp.775-791
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    • 2015
  • An analytical and experimental investigation is performed into the mechanical behavior of carbon-fiber/epoxy woven coned annular disk springs. An analytical approach is presented for predicting the deformation behavior of disk springs of specially orthotropic laminates with arbitrary geometric parameters. In addition, an analytical methodology is proposed for obtaining the deformation behavior of a stack of disk springs. The methodology is capable of accounting for parallel and series arrangements for uniform and irregular stacks. Element and assembly experimental results are used to validate the proposed method showing how to achieve flexible spring rates at various deflections ranges. This manuscript also provides guidelines for design and validation of disk spring assemblies.

Analysis of Post-tensioned Slab Bridge by Means of Specially Orthotropic Laminates Theory (특별직교이방성 복합적층판 이론을 응용한 포스트텐션된 슬래브 교량의 해석)

  • Han, Bong Koo;Kim, Yun Pyo
    • Journal of Korean Society of Steel Construction
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    • v.14 no.1
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    • pp.105-111
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    • 2002
  • A post-tensioned slab bridge is analyzed by the specially orthotropic laminates theory. Both the geometry and the material of the cross section of the slab are considered symmetrical with respect to the mid-surface so that the bending extension coupling stiffness, $B_{ij}=0$, and $D_{16}=D_{26}=0$. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This bridge with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and the beam theory are used for analysis. The result of beam analysis is modified to obtain the solution of the plate analysis. The result of this paper can be used for post-tensioned slab bridge analysis by the engineers with undergraduate study in near future.