• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.81-89
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• 2003

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. The result of this paper can be used for reinforced concrete slab bridges analysis by the engineers with undergraduate study in near future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.855-861
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• 2011

We predict the rolled-strip profile for a 6-high mill using thin rolling theory and a numerical model. In the numerical model, we calculate the distributions of the contact pressures between the rolls and the rolling pressure between the strip and the work roll in the transverse direction using the geometric structure of the 6-high mill and the boundary conditions. We determine the distribution of the rolling pressure in the rolling direction via a thin-foil rolling model using Fleck's theory. We calculate the three-dimensional elastic deformation of the work roll using the pressures of the width and rolling directions. We then obtain the three-dimensional strip profile via the elastic deformation of the work roll during the rolling process. The profile is verified by a thin cold-rolling test and FE simulation.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.33-36
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• 2009

현행 도로교설계기준의 바닥판에 대한 설계방법은 휨 이론에 따라 바닥판을 단위 폭의 보로 보고 강도설계법으로 설계하고 있다. 그러나 실제 교량 바닥판의 파괴 형태는 펀칭에 의한 파괴이므로 바닥판의 극한성능은 펀칭전단강도를 토대로 평가해야 할 것이다. 하지만 기존에 연구된 결과로는 초간편 강합성 바닥판의 펀칭전단강도를 산정하기 어려워 이에 대한 연구가 필요한 실정이다. 본 연구에서는 개발된 초간편 강합성 바닥판의 펀칭전단성능을 파악하기 위하여 초간편 강합성 바닥판과 RC바닥판에 대한 펀칭전단실험을 실시하여 비교하여 보았다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1479-1485
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• 1991

본 연구에서는 고차판이론(higher order shear deformable plate theory)을 사용하여 DCB시편을 보형상이 아닌 실제의 얇은 판으로 해석하여 새로운 에너지해방률 식을 제시하고자 한다.한편, 이의 타당성을 입증하기 위하여 Gr/Ep 및 APC-2 복합 재료로 ASTM D30.02 round robin의 제안 방법에 의해 층간파괴인성치를 구하고, 또 이 강용이 제안한 Ae법에 의한 금속의 파괴인성치 결정법을 참고로 하여 미세파괴 초창기 의 층간파괴인성치를 결정하여 이론결과와 비교 검토한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.12
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• pp.1013-1020
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• 2017

In this study, the failure prediction of composite laminates under flexural loading is investigated. A FEA(finite element analysis) using 2D strain-based interactive failure theory. A pregressive failure analysis was applied to FEA for stiffness degradation with failure mode each layer. A three-point bending test based on the ASTM D790 are performed for cross-ply $[0/90]_8$ and quasi-isotropic $[0/{\pm}45/90]_{2s}$ laminated composites. The accuracy of the applied failure theory is verified with the experimental results and other failure criteria such as maximum strain, maximum stress and Tsai-Wu theories.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.206-207
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• 2000

반사형 LCD는 주변광을 광원으로 사용하므로 높은 반사율과 주변환경을 고려한 시야각 특성을 요구한다. 이러한 반사형 LCD의 성능을 결정하는 요소로서는 반사판, 보상판 그리고 LCD의 구조가 있다. 반사형 LCD용 반사판은 최적의 디스플레이를 위해 반사되는 빛의 방향을 조절하고 사용자 위주의 시야각을 형성 할 수 있어야 한다. 본 연구에서는 이러한 반사특성을 나타내기 위한 조건을 이해하고, 특히 넓은 시야각 확보를 위해 표면구조에 따른 중요 파라미터와 그 최적 조건을 찾아내어 이론적으로 접근하고자 하였다.$^{(1,2)}$ (중략)

• Journal of the Korean Society of Safety
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• v.10 no.2
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• pp.129-133
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• 1995

A new approach to the analysis of thin. rectangular window giass glass supported on flexible gaskets. and subjected to uniform lateral pressures was evolved. Based on the Von Karman theory of plates and using the finite difference method. a computer program which determines the deflections and stresses in simply supported thin glass plates was developed.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.55-67
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• 1999

The ratios of elastic to shear modulus of the structures as laminated composite plates and shells, are very large. They are much susceptible to effect of shear deformation. In order to obtain the accurate solutions of laminated composite plate and shells, the effects of shear strain should be considered for the analysis and design of them. Especially, the more exact solution can be obtained in applying to higher-order shear deformation theory. Therefore, in this paper, the third-order shear deformation theory is used to present the distributions of bending, the characteristics of natural frequencies and the buckling load according to the effects of ply orientation, number of layers for the laminated composite plates and shells with simply supported boundary conditions.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.443-455
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• 2001

An energy method has been used for an elastic formulation of bending vibration and buckling analysis of laminated composite plates on two-parameter elastic foundations. A quasi-elastic method is used for the solution of viscoelastic analysis of the laminated composite plates. The third-order shear deformation theory is applied by using the double-fourier series. To validate the derived equations the obtained displacements for simply supported orthotropic plates on elastic foundations are compared with those of LUSAS program Numerical results of the viscoelastic bending vibration and buckling analysis are presented to show the effects of layup sequence number of layers material anisotropy and shear modulus of foundations.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.74-79
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• 2008

In this study, impact transient responses of (Graphite/Epoxy) laminated composite subjected to low-velocity impact are investigated using a finite element method. Dynamic von-Karman plate equations considering large deflection of plate are modified to include the effect of transverse shear deformations as in Mindlin plate theory and also the rotary inertia effect is considered. The convergence of transient responses is used contact law established through the statical indentation test. We investigate displacements, contact forces and strains by thickness variation of various laminated composite. We compare and analyze each results.