Improved Stability Design of Plane Frame Members

평면프레임 구조의 개선된 좌굴설계

  • Received : 2005.11.15
  • Accepted : 2006.03.13
  • Published : 2006.04.27

Abstract

Based on the study conducted by Kim et al. (205a, b), an improved stability design method for evaluating the effective buckling lengths of beam-column members is proposed herein, using system elastic/inelastic buckling analysis and second-order elastic analysis. For this purpose, the stress-strain relationship of a column is inversely formulated from the reference load-carrying capacity proposed in design codes, so as to derive the tangent modulus of a column as a function of the slenderness ratio. The tangent stiffness matrix of a beam-column element is formulated using the so-called "stability functions," and elastic/inelastic buckling analysis Effective buckling lengths are then evaluated by extending the basic concept of a single simply-supported column to the individual members as one component of a whole frame structure. Through numerical examples of several structural systems and loading conditions, the possibilities of enhancement in stability design for frame structures are addressed by comparing their numerical results obtained when the present design method is used with those obtained when conventional stability design methods are used.

김 등(2005a, b)의 연구를 확장시켜 시스템 좌굴 고유치해석법을 이용한 유효좌굴길이 산정법과 2차 탄성해석기법을 이용한 2차모멘트를 이용하여 축력과 휨모멘트를 받는 라멘구조의 보-기둥부재에 대한 개선된 좌굴설계법을 제안한다. 이를 위하여 먼저 국내도로교설계기준, AISC-LRFD, SRC의 각 설계기준에 제시된 내하력 기준식을 이용하여 응력-변형율 관계를 유도하고, 이를 이용한 탄성 및 비탄성 좌굴 고유치해석을 이용한 유효좌굴길이 산정법을 고찰한다. 또한 라멘구조에 대하여 AISC-LRFD에서 제시하고 있는 좌굴 안정성 검토식과 본 연구에서 제시하는 안정성 검토식을 해석예제를 통하여 비교, 검토를 행한다.

Keywords

Acknowledgement

Supported by : 교량설계핵심기술연구단

References

  1. 김문영, 송주영, 경용수, 김남일, (2005a), 탄성좌굴 고유치 및 2차 탄성해석법을 이용한 평면강절프레임의 개선된 좌굴설계법, 전산구조공학회논문집, 제 18권, 제 2호, pp159-168
  2. 김문영, 송주영, 경용수, (2005b), 탄성 및 비탄성 좌굴 고유치해석을 이용한 강뼈대구조의 유효좌굴길이, 전산구조공학회논문집, 제 18권, 제 2호, pp.169-179
  3. 진만식, 경용수, 김문영, (2004), 평면프레임의 좌굴설계를 위한 정확한 유효좌굴계수 산정, 대한토목학회논문집, 제24권, 제 3A호, pp.509-516
  4. 한국도로교통협회, (2005), 도로교설계기준
  5. American Institute of Steel Construction, (2002), AASHTO LRFD Bridge Design Specifications, 2nd ed, Chicago. IL
  6. Cheong-Siat-Moy, F. (1986), K-factor paradox, Journal of Structural Engineering, ASCE, Vol.112, No.8. pp.1747-1760 https://doi.org/10.1061/(ASCE)0733-9445(1986)112:8(1747)
  7. Duan, L., King, W.-S. and Chen, W.-F.(1993), K-Factor Equation to Alignment Charts for Column Design, ACI Structural Journal, Vol.90 No.3, pp.242
  8. Galambos, T. V., (1988), Guide to Structural Stability Design Criteria for Metal Structures, 4th.Ed., John Wiley and Sons, New York
  9. J. Dario Aristizabal-Ochoa, (1994), K-factor for Columns in Any Type of Construction : Nonparadoxical Apporach, Journal of Structural Engineering, ASCE, Vol.120, No.4, pp.1272-1290 https://doi.org/10.1061/(ASCE)0733-9445(1994)120:4(1272)
  10. LeMessurier, W. J., (1977), A Practical Method of Second Order Analysis, Part 2-Rigid Frames, Engineering Journal, AISC, 2nd Qtr., pp.49-67
  11. Louis F. Geschwindner, (2002), A Practical Look at Frame Analysis, Stability and Leaning Columns, Engineering Journal, Vol.39, No.4, pp167-181
  12. Roddis, W. M. K., Hamid, H. A and Guo, C. Q., (1998), Factors for Unbraced Frames: Alignment Chart Accuracy for Practical Frame Variations, Engineering Journal, Vol.35 No.3, pp.81-93
  13. Yura, J. A., (1971), The Effective Length of Column in Unbraced Frames, Engineering Journal, AISC, Vol.8 No.2, pp.49-67