U-flanged truss beam is composed of u-shaped upper steel flange, lower steel plate of 8mm or more thickness, and connecting lattice bars. Upper flange and lower plate are connected by the diagonal lattice bars welded on the upper and lower sides. In this study the structural experiments on the U-flanged truss beams with various shapes of upper flange were performed, and the flexural and shear capacities of U-flanged truss beam in the construction stage were evaluated. The principal test parameters were the shape of upper flange and the alignment space of diagonal lattice bars. In all the test specimens, the peak loads were determined by the buckling of lattice bar regardless of the upper flange shape. The test results have shown that the buckling of lattice bar is very important design factor and there is no need to reinforce the basic u-shaped upper flange. However, the early lattice buckling occurred in the truss beam with upper steel bars because of the insufficient strength and stiffness of upper chord, and the reinforcement in the upper chord is necessary. The formulae of Eurocode 3 (2005) have presented more exact evaluations of lattice buckling load than those of KBC 2016.

Abstract
 1. 서론
 2. 실험 계획
  2.1 실험체 계획
  2.2 가력 방법 및 측정 방법
 3. 실험 결과 및 분석
  3.1 금속 재료 인장 시험
  3.2 파괴 양상
  3.3 하중-변위 관계 곡선 분석
  3.4 기준식과의 내력 비교
 4. 결론
 References

• 오명호(국립목포대학교 건축공학과) | Oh Myoung Ho (Dept. of Architectural Engineering, Mokpo National Univ.)
• 김영호(엔테이지) | Kim Young Ho (NTAGE)
• 강재윤(한국건설기술연구원 인프라안전연구본부) | Kang Jae Yoon (Dept. of Infrastructure Safety Research, Korea Institute of Civil Engineering and Building Technology)
• 김명한(국립목포대학교 건축공학과) | Kim Myeong Han (Dept. of Architectural Engineering, Mokpo National Univ.) 교신저자