Journal of Korean Society of Steel Construction (한국강구조학회 논문집)

Korean Society of Steel Construction (한국강구조학회)
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Torsional Analysis of Thin-Walled Open Beams Using Effective Torsional Constants

유효비틀림계수를 사용한 박벽개보의 비틀림해석

  • 백성용 (인제대학교 토목공학과)
  • Received : 2006.01.14
  • Accepted : 2006.03.03
  • Published : 2006.04.27
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Abstract

This paper presents a new, effective torsional constant for thin-waled open beams under concentrated and uniformly distributed torques. The proposed constant can be used directly, instead of the St. Venant torsional constant, for any generic comemrcial finite-element program, without modifying the algorithm. The derived torsional constant accounts for both the pure torsion and the warping torsion, and is equal to the St. Venant torsion constant times a correction factor. It is also shown, in the case of the St. Venant torsion, that the derived constant is identical to the torsional constant. The derived effective torsional constant is different from the one given by Elhelbawey et al. The pure torsional shear stress, the warping shear stress, and the warping normal stress were also determine d, using the maximum twisting angle. The accuracy of the proposed torsional constant was validated by comparing the numerical results with the closed-form solutions or other numerical results available in the literature.

본 논문에서는 집중 비틂모멘트와 등분포 비틂모멘트가 작용하는 박벽개보의 뒴구속에 대한 영향을 고려할 수 있는 새로운 유효비틀림계수를 제시한다. 상용 유한요소 프로그램의 알고리즘을 바꾸지 않고 순수 비틀림계수 대신에 제안된 비틀림계수를 직접 사용할 수 있다. 유도된 비틀림계수는 순수 비틀림과 뒴 비틀림에 의한 영향을 고려하며 순수 비틀림계수에 보정계수를 곱하여 산정한다. 순수 비틀림의 경우 유도된 계수는 순수 비틀림계수와 일치하게 나타났다. 순수 비틀림을 이용하여 본 연구에서 유도한 유효 비틀림계수는 Elhelbawey 등이 제안한 비틀림계수와 차이를 보여주고 있다. 또한, 유효 비틀림계수를 사용하여 구한 최대비틀림각을 이용하여 부재 내 에 발생하는 전단응력과 다른 연구자의 결과들과 비교, 검토한다.

Keywords

References

  1. 곽효경, 이환우 (1998) 뒴의 영향을 고려한 보의 기하학적 비선형 해석, 대한토목학회논문집, 제 18권 I-3호, pp. 345-355
  2. 박효기, 김성보, 김문영, 장승필 (1999) 비대칭단면을 갖는 박벽 공간뼈대구조의 횡-비틂 후좌굴 유한요소해석, 한국강구조학회논문집, 제 11권 2호, pp. 153-165
  3. AISC (2001) Manual of Steel Construction: Load and Resistance Factor Design, 3rd ed., American Institute of Steel Construction, Chicago
  4. Back, S. Y. and Will, K. M. (1998) A Shear-Flexible Element with Warping for Thin-Walled Open Beams, International Journal for Numerical Methods in Engineering, Vol. 43, pp. 1173-1191 https://doi.org/10.1002/(SICI)1097-0207(19981215)43:7<1173::AID-NME340>3.0.CO;2-4
  5. Chen, H. and Blandford, G. E. (1989) A $C^o$ Finite Element Formulation for Thin-Walled Beams, International Journal for Numerical Methods in Engineering, Vol. 28, pp. 2239-2255 https://doi.org/10.1002/nme.1620281004
  6. Elhelbawey, M. I. and Fu, C. C. (1998) Effective Torsional Constant for Restrained Open Section, Journal of Structural Engineering, ASCE, Vol. 124, No. 11, pp. 1363-1365 https://doi.org/10.1061/(ASCE)0733-9445(1998)124:11(1363)
  7. GTICS System Laboratory, (2005) School of Civil Engineering, Georgia Institute of Technology, GTSTRUDL User's Manual, Vol. 3, Atlanta, Georgia, U.S.A
  8. Heins, C. P. (1975) Bending and Torsional Design in Structural Members, Lexington Books, Lexington, Massachusetts
  9. Seaburg, P. A. and Carter, C. J. (1997) Torsional Analysis of Structural Steel Members, American Institute of Steel Construction, Chicago, IL
  10. Timoshenko, S. P. and Gere, J. M. (1961) Theory of Elastic Stability, McGraw-Hill, New York, U.S.A
  11. Tralli, A. (1986) A Simple Hybrid Model for Torsion and Flexure of Thin-Walled Beams, Computers & Structures, Vol. 22, pp. 649-658 https://doi.org/10.1016/0045-7949(86)90017-9
  12. Vlasov, V. Z. (1961) Thin-Walled Elastic Beams, Israel Program for Scientific Translations
  13. Yang, Y. and McGuire, W. (1986) A Stiffness Matrix for Geometric Nonlinear Analysis, Journal of Structural Engineering, ASCE, Vol. 112, No. 4, pp. 853-877 https://doi.org/10.1061/(ASCE)0733-9445(1986)112:4(853)