FRP 바닥판의 약축방향 파괴모드에 관한 연구 = A Study on the Failure Mode of FRP Bridge Deck in It's Weak Axis

국문 초록 (Abstract)

본 논문에서는 내구성과 수명을 획기적으로 향상시키기 위해 제3세대 건설재료인 섬유강화 플라스틱(FRP) 소재로 제작된 사각형 중공 교량 바닥판의 파괴모드를 실험과 해석을 통해 분석하였다. 재하시험 결과 바닥판의 강축방향의 거동은 파괴 직전까지도 거의 선형탄성적으로 거동한 반면, 약축방향의 거동은 재하초기부터 작은 하중하에서도 큰 비선형성을 보였다. 이 약축방향 비선형성의 원인은 웨브와 플랜지 연결부의 불완전한 일체거동으로 인한 소성거동 때문인 것으로 판단된다. 웨브와 플랜지의 연결부에 소성힌지를 도입한 간단한 구조모델을 이용하여 이를 확인하였다. 접착부의 박리 파괴 가능성도 검토하였으나 이는 대상 중공바닥판의 약축방향 파괴에 직접적으로 관여하는 것은 아닌 것으로 판단된다 약축방향의 구조거동을 개선시키기 위한 방안으로 내부를 폼으로 충전하는 방법을 제시하였으며 그 가능성을 구조해석을 통해 확인하였다.

다국어 초록 (Multilingual Abstract)

The failure mechanism of a hollow bridge deck which is made of fiber reinforced polymer (FRP) to improve its durability and life time significantly is investigated using both experiments and analyses. While the Load-displacement behavior of the deck in the longitudinal direction is almost linear just before the failure, the behavior in the transverse direction shows a strong nonlinearity even in its initial response with relatively small magnitude of loads. We found that the nonlinearity is due to the imperfection of the connection between the flange and the web; a plastic deformation can t라e place in the connection. The argument is demonstrated using a simple structural model in which a rigid plastic hinge is introduced to the connection. We also checked the contribution of the delamination mechanism to the failure. But the delamination is not the main mechanism which initiates and causes the failure of the bridge deck. In order to improved the structural behavior of the deck in the transverse direction, we suggested that the empty space of the bridge deck is filled with a foam and confirmed the improved behavior by a numerical analysis.

참고문헌 (Reference)

1 "장수명 합리화 바닥판 개발 II (2차년도)" 2003

2 "장수명 합리화 바닥판 개발 II (1차년도)" 2002

3 "경량 고내구성 복합소재 교량 바닥판의 개발" 대한토목학회 682-685, 2001

4 "The extended finite element method for dynamic fractures" 12 (12): 9-23, 2005

5 "Static testing on FRP bridge deck panels. Proc., 44th Int. SAMPE Symposium and Exhibition" 1643-1654, 1999

6 "Stability of structures" Oxford university press 1991

7 "Size effect on strength of floating sea ice under vertical line load" 128 (128): 254-263, 2002

8 "Shear stud connections for the development of composite action between steel girders and fiber-reinforced polymer bridge decks" 128 (128): 762-770, 2002

9 "New crack-tip elements for XFEM and applications to cohesive cracks" 2221-2240, 2003

10 "Multiobjective material architecture optimization of pultruded FRP I beams" 35 (35): 271-281, 1996

11 "Modeling and characterization of fiber-reinforced plastic honeycomb sandwich panels for highway bridge applications" 52 (52): 441-452, 2001

12 "Extended finite element method for three-dimensional crack modeling" 48 (48): 1549-1570, 2000

13 "Engineering mechanics of composite materials" Oxford Unversity Press. 1994

14 "Eigenvalue method for computing size effect of cohesive cracks with residual stress, with application to kink bands in composites" 41 (41): 1517-1534, 2003

15 "Dynamic crack propagation based on loss of hyperbolicity with a new discontinuous enrichment" 58 (58): 1873-1905, 2003

16 "Development of glass fiber reinforced polymer composite bridge deck" 35 (35): 12-24, 1999

17 "Arbitrary discontinuities in finite elements" 50 (50): 993-1013, 2001

18 "Arbitrary branched and intersecting cracks with the extended finite element method" 48 : 1741-1760, 2000

19 "An extended finite element method for modelling crack growth with friction contact" 190 (190): 6825-6846, 2000

20 "A systematic approach for analysis and design of single-span FRP deck/stringer bridges" 31 (31): 593-610, 2000

21 "A method for growing multiple cracks without remeshing and its application to fatigue crack growth" 12 : 901-915, 2004b

22 "A method for growing multiple cracks without remeshing and its application to fatigue crack growth" 12 : 901-915, 2004b