Experimental and Analytical studies on Failure Behavior of Stud Shear Connectors in CFT Structures

CFT 구조에 적용된 스터드 전단연결재의 파괴 거동에 대한 실험 및 해석적 연구

  • Lee, Sangyoon (Structural Engineering Research Division of Korea Institute of Construction Technology)
  • Received : 2013.09.30
  • Accepted : 2013.12.03
  • Published : 2013.12.31

Abstract

For the composite behavior of steel tube and inner concrete, the shear connectors should be applied to the CFT structures. However, the present design codes don't provide the design criteria that can be applied on shear connectors in the CFT structures typically filled with plain concrete. This study has been carried out to propose design criteria (shear strength and resistance factor) for the stud shear connectors in CFT structures. Experimental tests using the push-out specimens with the plain concrete blocks and finite element analysis were conducted for the purpose of verifying the main failure mode to propose the shear strength of studs in CFT structures. From the results of this study, the main failure mode of studs in CFT structures is splitting crack of concrete and this failure mode reduces shear strength of studs in CFT structures relatively to those embedded in RC blocks.

CFT 구조는 내부의 콘크리트와 강관의 합성거동을 위한 전단연결재를 필요로 한다. 하지만, 현행 설계기준에서는 통상적으로 무근콘크리트로 채워지는 CFT 구조에 적용할 수 있는 전단연결재에 대한 설계기준을 제시하고 있지 않다. 본 연구는 강-콘크리트 합성구조에 널리 사용되는 스터드 전단연결재를 CFT 구조에 적용하기 위한 설계기준 즉, CFT 구조에 적용된 스터드 전단연결재의 전단강도를 제안하기 위한 연구의 일환으로 수행되었다. 본 연구에서는 CFT 구조에 적용된 스터드의 전단강도를 결정하는 주된 파괴모드를 검토하기 위하여 무근콘크리트를 적용한 직접전단실험체를 이용하여 실험을 수행하고 파괴모드를 분석하기 위한 유한요소해석을 실시하였다. 직접전단실험 및 유한요소해석결과로부터 CFT 구조에 적용된 스터드 전단연결재의 주된 파괴모드는 콘크리트의 쪼갬파괴이며, 이러한 파괴모드로 인하여 철근콘크리트에 적용된 스터드에 비해 전단강도가 감소한다는 사실을 확인할 수 있었다.

Keywords

Acknowledgement

Supported by : 한국건설기술연구원

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