압축플랜지 비탄성 국부좌굴을 고려한 HSB 플레이트거더의 휨강도 = Flexural Strength of HSB I-Girder Considering Inelastic Flange Local Buckling

국문 초록 (Abstract)

HSB를 적용한 플레이트거더의 압축플랜지 국부좌굴을 고려한 극한휨강도를 비선형 유한요소해석으로 분석하였다. 압축플랜지의 비탄성 국부좌굴 또는 소성항복이 휨강도를 지배하는 압축플랜지 세장비를 갖도록 해석대상 강거더를 선정하였다. HSB600 및 HSB800 강재로 제작된 균질단면 강거더와 HSB800 강재와 SM570-TMC 강재를 함께 적용한 하이브리드 단면을 고려하였으며, 일반강재와의 비교를 위하여 SM490-TMC 강거더에 대한 해석도 수행하였다. 비선형 유한요소해석 시에는 플랜지와 복부판을 쉘요소로 강재는 탄소성-변형경화 재료로 모델링하였으며, 초기변형과 단면의 잔류응력을 고려하였다. 비선형 유한요소해석 결과와 기존 문헌의 실험결과를 비교하여 유한요소 해석결과를 검증하였으며, 초기변형과 잔류응력이 극한휨강도에 미치는 영향을 분석하였다. 총 60개 해석대상 강거더의 휨극한강도를 유한요소해석으로 구하고, 도로교설계기준, AASHTO LRFD와 Eurocode 3의 설계규정으로 구한 휨강도와 비교하여 이들 규정의 HSB 강거더에 대한 적용성을 검토하였다.

다국어 초록 (Multilingual Abstract)

The ultimate flexural strength of HSB I-girders, considering the effect of local bucking, was investigated through a series of nonlinear finite element analysis. The girders were selected such that the inelastic local flange buckling or the plastic yielding of compression flanges governs the flexural strength. Both homogeneous sections fabricated from HSB600 or HSB800 steel and hybrid sections with HSB800 flanges and SM570-TMC web were considered. In the FE analysis, the flanges and web were modeled using thin shell elements and initial imperfections and residual stresses were imposed on the FE model. An elasto-plastic strain hardening material was used for steels. After establishing the validity of present FE analysis by comparing FE results with test results published in the literature, the effects of initial imperfection and residual stress on the inelastic flange local buckling behavior were assessed. The ultimate flexural strengths of 60 I-girders with various compression flange slenderness were obtained by FE analysis and compared with those calculated from the KHBDC, AASHTO LRFD and Eurocode 3 provisions. Based on the comparison, the applicability of design equations in these specifications for the flexural strength of I-girder considering flange local buckling was evaluated.

참고문헌 (Reference)

1 Timoshenko, S. P, "Theory of Elastic Stability" McGraw-Hill 1961

2 Green, "The Inelastic Behavior of Flexural Members Fabricated from High Performance Steel" Lehigh University 2000

3 Yura, J. A., "The Bending Resistance of Steel Beams" ASCE 104 (104): 1355-1370, 1978

4 Lukey, A. F, "Rotation Capacity of Beams Under Moment Gradient" ASCE 95 (95): 1173-1188, 1969

5 McDermott, J. F., "Plastic Bending of A514 Steel Beams" ASCE 95 (95): 1851-1871, 1969

6 AISC, "Manual of Steel Construction, Load & Resistance Factor Design" American Institute of Steel Construction 1986

7 KHBDC, "Korean Highway Bridge Design Code(Limit State Design)"

8 Lay, M. G, "Inelastic Beams Under Moment Gradient" ASCE 93 (93): 381-399, 1967

9 Lay, M. G, "Inelastic Beams Under Moment Gradient" ASCE 91 (91): 67-93, 1965

10 Smith, R. J, "Experiments on Wide- Flange Beams under Moment Gradient" Department of Civil Engineering, University of Alberta 1968

11 Roik, K, "Experimentelle ermittlung der Rotationskapaziteit biegebeanspruchte I-Profile" 56 (56): 353-358, 1987

12 Eurocode 3, "Design of steel structures. Part 1-5: Plated structural elements"

13 Eurocode 3, "Design of steel structures. Part 1-1: General rules and rules for buildings"

14 AWS, "Bridge Welding Code, ANSI/AASHTO/AWS D1.5-95" Joint Publication of American Association of State and Highway Transportation Officials and American Welding Society 239-, 1995

15 Johnson, D. L, "An Investigation into the Interaction Flange and Webs in Wide Flange Shapes" Gainesville 1985

16 Hibbit, Kalsson, "ABAQUS/CAE Version 6.8. Standard user's manual" Rhode Island 2008

17 American Association of State and Highway Transportation Officials, "AASHTO LRFD Bridge Design Specifications" Washington 2012

18 American Association of State and Highway Transportation Officials, "AASHTO LRFD Bridge Design Specifications" Washington 1996