• Title/Summary/Keyword: code formula

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Brief Review of Studies on Concrete Wall Panels in One and Two Way Action

  • Doh, Jeung-Hwan;Fragomeni, Sam;Kim, Jin-Woo
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • v.4 no.1
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    • pp.38-43
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    • 2001
  • This paper provides review of research results undertaken on reinforced concrete wall panels in one way and two way. The review also highlights two well accepted code design methods from the American (ACI) and Australia Concrete structures standards. The emphasis is on walls under axial compression only with changes in various parameters. These include the variation of panel dimensions panels (ie. Slenderness, thinness and aspect ratios), steel reinforcement, eccentricities, concrete strength and support conditions. The main purpose of this review is to compile research previous by undertaken to highlight the inadequate in certain research literature. It is envisage that this review will expose areas in wall research required so that inadequate in current methods can be rectified.

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Coupled CFD-FE Analysis Method for IC Engine Cooling Water Jacket under Subcooled Nucleate Boiling Conditions (핵비등 열전달 효과를 고려한 내연기관 냉각수로의 CFD-FE 연성해석 기법)

  • Lee, Myung-Hoon;Kim, Dong-Kwang;Lee, Sang-Kyoo;Rhim, Dong-Ryul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.5
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    • pp.9-16
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    • 2006
  • The present study is to simulate coolant flow in IC engine cooling passages under subcooled nucleate boiling conditions and investigate thermal stress analysis of the solid part. To consider nucleate boiling heat transfer effect, Chen's empirical formula is used through user subroutine programing in CFD code and then nucleate boiling model is compared with Robinson's experimental results, which shows reasonable agreement. This Chen's nucleate boiling model is applied to single cylinder IC engine model and we do cylinder liner thermal stress analysis using commercial FEM code.

Turbulent Natural Convection in a Hemispherical Geometry Containing Internal Heat SourcesZ

  • Lee, Heedo;Park, Goon-cherl
    • Nuclear Engineering and Technology
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    • v.30 no.6
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    • pp.496-506
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    • 1998
  • This paper deals with the computational modeling of buoyancy-driven turbulent heat transfer involving spatially uniform volumetric heat sources in semicircular geometry. The Launder & Sharma low-Reynolds number k-$\varepsilon$ turbulence model without any modifications and the SIMPLER computational algorithm were used for the numerical modeling, which was incorporated into the new computer code CORE-TNC. This computer code was subsequently benchmarked with the Mini-ACOPO experimental data in the modified Rayleigh number range of 2$\times$10$^{13}$ $\times$10$^{14}$ . The general trends of the velocity and temperature fields were well predicted by the model used, and the calculated isotherm patterns were found to be very similiar to those observed in previous experimental investigations. The deviation between the Mini-ACOPO experimental data and the corresponding numerical results obtained with CORE-TNC for the average Nusselt number was less than 30% using fine grid in the near-wall region and the three-point difference formula for the wall temperature gradient. With isothermal pool boundaries, heat was convected predominantly to the upper and adjacent lateral surfaces, and the bottom surface received smaller heat fluxes.

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POSET METRICS ADMITTING ASSOCIATION SCHEMES AND A NEW PROOF OF MACWILLIAMS IDENTITY

  • Oh, Dong Yeol
    • Journal of the Korean Mathematical Society
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    • v.50 no.5
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    • pp.917-931
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    • 2013
  • It is known that being hierarchical is a necessary and sufficient condition for a poset to admit MacWilliams identity. In this paper, we completely characterize the structures of posets which have an association scheme structure whose relations are indexed by the poset distance between the points in the space. We also derive an explicit formula for the eigenmatrices of association schemes induced by such posets. By using the result of Delsarte which generalizes the MacWilliams identity for linear codes, we give a new proof of the MacWilliams identity for hierarchical linear poset codes.

Development of Positive Moment Reinforcement (정모멘트 철근의 정착)

  • 홍성걸
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.421-426
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    • 1998
  • Current code provisions for the development of positive moment reinforcement is reviewed and criticized in this paper. Both the flexural bond and development length concepts are neccesary to consider anchorage requirement of reinforcement at beam ends. The curent design codes show unconservatism for the detailing of reinforcement at the beam ends. This study proposes a new design formula for the development of positive moment reinforcement.

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A Derivation of Shear Strength Equation based on Arch Action in Reinforced Concrete Beams (R/C 보에서 아취현상에 기초한 전단강도 산정)

  • Kim, Woo;Kim, Dae-Joong
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.299-304
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    • 1995
  • An equation is proposed to predict ultimate shear strength. The equatiion on ultimate shear strength, which is purely based on analytical premises, is similar form to ACI code(11-6) which is derived mainly from empirical approach. Furthermore, the strength predicted by the proposed equation show better correlation with the tested values than the values calculated by Zsutty's formula.

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Assessment of Flexural Crack Width and Crack Spacing of Reinforced Concrete Beams (RC보의 휨 균열폭 및 균열간격에 관한 실험 및 이론 연구)

  • 오병환;김세훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.105-108
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    • 2000
  • With exact analysis of cracks in RC beam, present or past stress states can be traced. For analysis of Flexural cracks, experiments are carried out focusing on variation of crack widths and crack spacing due to stress, beam properties. The crack width expectation formulas of each code are compared and initial crack spacing expectation formula is proposed.

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Strength Models dependent on Load Configurations (하중형상과 콘크리트 부재의 강도모형)

  • Hong, Sung-Gul
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.843-846
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    • 2008
  • Rationality of strength models for structural concrete depends on how to treat loads on boundaries and load paths within members. Differentiation between strut-and-tie models and stress fields approaches for shear strength models is discussed in this paper for salient use of current design formula in design code provisions. How to model configuration of loads and stress states along the boundary for the regions under provides a key to realistic construction of stress fields together with STM.

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Vertical distributions of lateral forces on base isolated structures considering higher mode effects

  • Tsai, C.S.;Chen, Wen-Shin;Chen, Bo-Jen;Pong, Wen-Shen
    • Structural Engineering and Mechanics
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    • v.23 no.5
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    • pp.543-562
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    • 2006
  • Base isolation technology has been accepted as a feasible and attractive way in improving seismic resistance of structures. The seismic design of new seismically isolated structures is mainly governed by the Uniform Building Code (UBC-97) published by the International Conference of Building Officials. In the UBC code, the distribution formula of the inertial (or lateral) forces leads to an inverted triangular shape in the vertical direction. It has been found to be too conservative for most isolated structures through experimental, computational and real earthquake examinations. In this paper, four simple and reasonable design formulae, based on the first mode of the base-isolated structures, for the lateral force distribution on isolated structures have been validated by a multiple-bay three-story base-isolated steel structure tested on the shaking table. Moreover, to obtain more accurate results for base-isolated structures in which higher mode contributions are more likely expected during earthquakes, another four inertial force distribution formulae are also proposed to include higher mode effects. Besides the experimental verification through shaking table tests, the vertical distributions of peak accelerations computed by the proposed design formulae are in good agreement with the recorded floor accelerations of the USC University Hospital during the Northridge earthquake.