• Title/Summary/Keyword: Formulae

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Towards a consistant safety format of steel beam-columns: application of the new interaction formulae for ambient temperature to elevated temperatures

  • Vila Real, P.M.M.;Lopes, N.;Simoes da Silva, L.;Piloto, P.;Franssen, J.M.
    • Steel and Composite Structures
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    • v.3 no.6
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    • pp.383-401
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    • 2003
  • Two new formulae for the design of beam-columns at room temperature have been proposed into Eurocode 3, prEN 1993-1-1 (2002), and are the result of great efforts made by two working groups that followed different approaches, a French-Belgian team and an Austrian-German one. Under fire conditions the prEN 1993-1-2 (structural fire design) presents formulae, for the design of beam-columns based on the prENV 1993-1-1 (1992). In order to study the possibility of having, in part 1-1 and part 1-2 of the Eurocode 3, the same approach, a numerical research was made using the finite element program SAFIR, developed at the University of Liege for the study of structures subjected to fire.

Lift and Drag of a Circular Cylinder by the Discrete Vortex Method (이산 보오텍스법에 의한 원주의 양력 및 항력)

  • D.K.,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.2
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    • pp.40-46
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    • 1990
  • Expressions for the lift and the drag exerted on a circular cylinder by an unsteady flow of an ideal fluid with embedded discrete vortices are derived. The formulae can be used in the discrete vortex method of flow simulation. These formulae are derived via contour integration on the complex plane. Terms have been produced which are significantly different from those in Sarpkaya's formulae. These are expected to bring a change to the forces obtained so far.

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Development of Deformation Predicting Model for Line Heating of Steel Plates (강판의 선상가열시 변형량 예측모델의 개발)

  • Lim, Dong-Yong;Lee, Joo-Sung
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.10a
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    • pp.121-126
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    • 2003
  • This paper is concerns with the development of the formulae to predict deformation of curved plate due to line heating. For this purpose thermal elasto-plastic analysis has been carried out for both flat and curved plate models with varying parameters which affect the result of line heating. based on the results of numerical analysis, the formulae for predicting angular deformation has been derived through the regression analysis, which. It has been seen that the present model well agrees with the numerical analysis results and can reflect the curvature effect of plate to be heated. This paper ends with some comments on this formulae.

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Correction of CIEDE2000 Color Difference Formula for the Analysis of Low Chroma and Low Lightness Colors

  • Woo Hwa-Lyung;Kim, Sam-Soo;Hudson Samuel M.
    • Textile Coloration and Finishing
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    • v.18 no.5 s.90
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    • pp.72-79
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    • 2006
  • There are many discrepancies between visually perceived color-difference and that which is quantified from an instrumental measurement when dark color samples are measured in the textile industry. The samples were prepared to represent these dark shades and the values of the instrumental results from conventional color-difference formulae(CIELAB, CMC, BFD II, CIE94, LCD99 and CIEDE2000). Those of visual assessment were compared. The experimental results show that the CIELAB formula gives the best performance over other formulae, and the CIEDE2000 formula for the color-difference according to chroma presents the worst performance. Therefore, we can say that the problems in color matching of dark shades are caused by imperfect formula, because the results obtained from a color-difference formulae are different and the CMC which is used as a standard color-difference formula in the textile industry is not correct. So, a revised color-difference formula is proposed in this study, to account for these problems.

Finite element generalized tooth contact analysis of double circular arc helical gears

  • Qu, Wentao;Peng, Xiongqi;Zhao, Ning;Guo, Hui
    • Structural Engineering and Mechanics
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    • v.43 no.4
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    • pp.439-448
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    • 2012
  • This paper investigates the load sharing of double circular arc helical gears considering the influence of assembly errors. Based on a load sharing formulae, a three-dimensional finite element tooth contact analysis (TCA) is implemented with commercial software package ANSYS. The finite element grid for the double circular arc gear contact model is automatically generated by using the APDL (ANSYS Parameter Design Language) embedded in ANSYS. The realistic rotation of gears is achieved by using a coupling degree-of-freedom method. Numerical simulations are carried out to exemplify the proposed approach. The distribution of contact stress and bending stress under specific loading conditions are computed and compared with those obtained from Hertz contact theory and empirical formulae to demonstrate the efficiency of the proposed load sharing calculation formulae and TCA approach.

Effective lengths of braced frame columns

  • Girgin, Konuralp;Ozmen, Gunay
    • Structural Engineering and Mechanics
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    • v.28 no.2
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    • pp.189-206
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    • 2008
  • In several design codes and specifications, simplified formulae and charts are given for determining the effective lengths of frame columns. It is shown that these formulae may yield rather erroneous results in certain cases. This is due to the fact that, the code formulae utilise only local stiffness distributions. In this paper, a simplified procedure for determining approximate values for the buckling loads of braced frames is developed. The procedure utilises a fictitious load analysis of frames and yields errors less than 10%, which may be considered suitable for design purposes. The proposed procedure is applied to several numerical examples and it is shown that all the errors are in the acceptable range.

Buckling lengths of unbraced multi-storey frame columns

  • Ozmen, Gunay;Girgin, Konuralp
    • Structural Engineering and Mechanics
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    • v.19 no.1
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    • pp.55-71
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    • 2005
  • In several design codes and specifications, simplified formulae and diagrams are given for determining the buckling lengths of frame columns. It is shown that these formulae may yield rather erroneous results in certain cases. This is due to the fact that, the code formulae utilise only local stiffness distributions. In this paper, a simplified procedure for determining approximate values for the buckling loads of multi-storey frames is developed. The procedure utilises lateral load analysis of frames and yields errors in the order of 10%, which may be considered suitable for design purposes. The proposed procedure is applied to several numerical examples and it is shown that all the errors are in the acceptable range and on the safe side.

Development and Application of a Software Tool for the Interpretation of Organic Mixtures' Spectra - Hydrogen Deuterium Exchange (STORM-HDX) to Interpret APPI HDX MS Spectra

  • Lee, Sunghyup;Cho, Yunju;Kim, Sunghwan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.749-752
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    • 2014
  • New software was developed for the assignment of elemental formulae based on high-resolution mass spectra and subsequent hydrogen/deuterium exchange data. Entire peaks in high-resolution mass spectra were grouped by their Kendrick mass defect values, and the weighted RMS deviations between theoretical and experimental values were used to determine elemental formulae. After this initial assignment, formulae containing deuterium atoms were sorted in order to interpret hydrogen/deuterium exchange spectra. The software was successfully applied to hydrogen/deuterium exchange spectra of resins and aromatic fractions from heavy crude oil.

A review of seismic design recommendations in Jordan

  • Saffarini, Hassan S.
    • Structural Engineering and Mechanics
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    • v.9 no.3
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    • pp.257-268
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    • 2000
  • The seismic design recommendations of the Jordan Code for Loads and Forces (JC) are evaluated, based on comparisons with analytical studies and the Uniform Building Code. It was established that the overall safety ensured by the implementation of these recommendations is not consistent with the established seismic risk in Jordan and the intended objectives of the code. A new zoning map is proposed with effective peak ground acceleration values. The different period formulae of the code were studied and were found to grossly underestimate the fundamental period when compared with analytically derived values or other codes' formulae. Other factors including the dynamic, soil, importance and behavior factors are discussed. It was determined that the JC's lateral load distribution formulae clearly lead to smaller internal forces than both dynamic analysis and UBC loads, even when those loads are normalized to give the same base shear. The main reason for this is attributed to the limited allowance for a backlash force in the JC.

Eigenvalue Assignment for Linear Time-Varying Systems via Ackermann-like Formula (선형 시변 시스템의 고유치 지정을 위한 Ackermann형 공식)

  • 이호철;최재원
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.3
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    • pp.186-195
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    • 2003
  • This paper deals with eigenvalue assignment techniques for linear time-varying systems as a way of achieving feedback stabilization. For this, the novel eigenvalue concepts, which are the time-varying counterparts of the conventional (time-invariant) eigenvalue notions, are introduced. Then, the Ackermann-like formulae for SISO/MIMO linear time-varying systems are proposed. It is believed that these techniques are the generalized versions of the Ackermann formulae for linear time-invariant systems. The advantages of the proposed Ackermann-like formulae are that they neither require the transformation of the original system into the phase-variable form nor compute the eigenvalues of the original system. Two examples are given to demonstrate the capabilities of the proposed techniques.