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An Analytical Study of Flange Local Buckling of Horizontally Curved I-Girders for Estimate Resonable Stress Gradient

합리적 응력경도 산정을 위한 수평 곡선 I-형 거더의 플랜지 국부좌굴의 해석적 연구

  • Kim, Hee-Soo (School of Civil, Environmental and Architectural Engineering, Korea Univ.) ;
  • Lee, Kee-Sei (School of Civil, Environmental and Architectural Engineering, Korea Univ.) ;
  • Lee, Jeong-Hwa (School of Civil, Environmental and Architectural Engineering, Korea Univ.) ;
  • Choi, Jun-Ho (Research Institute for Mega Structures, Korea Univ.) ;
  • Kang, Young-Jong (School of Civil, Environmental and Architectural Engineering, Korea Univ.)
  • 김희수 (고려대학교 건축사회환경공학과) ;
  • 이기세 (고려대학교 건축사회환경공학과) ;
  • 이정화 (고려대학교 건축사회환경공학과) ;
  • 최준호 (고려대학교 초대형구조기술연구소) ;
  • 강영종 (고려대학교 건축사회환경공학과)
  • Received : 2015.08.18
  • Accepted : 2015.10.08
  • Published : 2015.10.31

Abstract

Horizontally curved I-girders are subjected to not only bending moments but also torsional moments. The torsional moment of the plate girder is addition of St. Venant torsion and non-uniform torsion. In the flange of I-shaped plate girder, a kind of open-section, the normal stresses is not distributed uniformly due to the non-uniform torsion. Because of that, one of compression flange tip can be yielded faster than the flange of general straight girder. In other words, the flange local buckling strength is decreased when the girder has initial curvature. In this paper, the numerical analysis is conducted to investigate the average stresses in flange for curved girders. The subtended angle and slenderness ratio are taken as parameters.

본 I-형 수평 곡선 거더는 휨모멘트뿐만 아니라 비틀림 모멘트를 동시에 저항하고 있으며, 플레이트 거더에 작용하는 비틀림 모멘트는 균일 비틀림과 불균일 비틀림의 조합으로 결정된다. 개단면으로서 I형 단면을 가진 플레이트 거더의 경우 불균일 모멘트에 의해서 플랜지에 작용하는 법선 응력은 불균일 분포를 보이며, 곡선거더 플랜지의 한쪽 연단은 휨 법선응력과 �� 법선응력이 중첩되어 일반적인 직선거더의 플랜지보다 더 빨리 항복하는 경향을 보이게 된다. 다시 말해, 초기 곡률이 적용된 거더는 직선 거더에 비해 플랜지에 작용하는 응력분포가 저하되는 양상을 보인다. 본 연구에서는 플랜지의 세장비와 거더의 곡률 중심각을 매개변수로 하여, 수치해석을 통해 곡선 거더의 플랜지에 작용하는 응력의 저하양상을 살펴보았다.

Keywords

References

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