• 콘크리트학회논문집
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• 제16권3호
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• pp.335-344
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• 2004

이 논문에서는 프리캐스트 콘크리트와 현장타설 콘크리트 그리고 긴장된 강재와 긴장되지 않은 강재 등으로 구성되는 합성단면에서 콘크리트 장기변형의 내부구속에 의한 잔류응력과 긴장력 손실을 해석하였다. 이 해석결과로부터 사용 중에 도입되는 추가 긴장력으로 합성거더를 보강하는 경우에 필요한 추가 긴장력의 설계식과 저항모멘트 평가식이 제안되었다. 제안된 식은 일차 긴장력의 손실률이 설계규준의 일괄손실 등에 의해 과대평가되는 경우에 허용응력으로부터 결정되는 추가 긴장력 또한 과대평가 될 수 있음을 보여준다. 일반적으로 많이 사용되는 AASHTO Type 5 거더의 합성단면에 대해 이 논문의 해석방법을 적용 및 검토하였다. 프리캐스트 콘크리트 거더에 추가 긴장력이 도입되는 경우 일차 긴장력과 추가 긴장력의 손실률은 합성거더에 도입되는 경우보다 작았으나, 저항모멘트는 합성거더에 추가 긴장력이 도입되는 경우 상당히 증가하였다. 합성거더에 도입된 추가 긴장력의 보강효과는 매우 우수하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.54-60
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• 1998

PSC box bridges by MSS construction method in high-speed railway may not be cast in place at one step. Web and bottom flange(U member) in the cross section are cast in place at first, then top flange will be cast in place later with some time lag. In this section, stress distributions of U member and top flange are different with those in generally complete cast in place cross section. In the composite section composed of two different aged members, the redistribution of stresses takes place. This results from time-dependent strain characteristics of concrete and the effects of forces applied at the various stages. For comparison in the present paper, two models, one with the composite cross section and the other with generally complete cast in place cross section, are analyzed. The longitudinal stress differences of two models on considering construction stages are compared. As the analysis results show the considerable differences in the stresses of cross section between two models, the composition of cross section is considered for rational design of PSC box girder bridge.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.480-485
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• 2004

The applications of composite materials have increased over the past few decades in a variety of structures that require high ratio of stiffness and strength to weight ratios. Recently the thick open section composite beams are used extensively as load carrying members and stiffeners of structural elements. However, most of studies on thick composite beams are limited only to closed section beams. In this study, an open cross-section thick-walled composite beam model which includes coupled stiffness, transverse shear, and warping effects is suggested and the deflections associated with the thick-walled composite beams and thin-walled composite beams are obtained and compared with the finite element analysis results.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.202-206
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• 2005

Most of studies on the open section composite beams are confined to the thin composite beams. There are some works focused on the thick composite beams but they are limited only to closed section beams. Therefore, it is required to develop an appropriate model to analyze the thick open section composite beams. In this study, the cantilever beams of two specific lay-up configurations are considered which are the circumferentially asymmetric stiffness (CAS) and circumferentially uniform stiffness (CUS) beams. Under the torsional loading, loading induced deformations are obtained for the thick beams using the suggested model. The model includes coupled stiffness and secondary warping effects. The results are compared with those obtained using thin beam model to observe the thickness effects. Those results are also compared with the finite element analysis results.

• 복합신소재구조학회 논문집
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• 제2권1호
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• pp.1-7
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• 2011

본 논문에서는 복합소재 방호울타리의 6가지 적층 단면에 대한 충돌시뮬레이션을 실시하여 최적 적층 단면을 결정하였다. 먼저 6가지 단면 형상에 대하여 설문 조사를 통하여 형상을 결정하였다. 결정된 보 단면에 대하여 6가지 적층설계를 하였다. 적층에는 CSM, DB, DBT, Roving 섬유를 사용하였다. LS-DYNA를 사용하여 수평 및 3:1 경사에 대한 복합소재 보를 모델링하였다. 직육면체 추 및 원통형 추를 사용하여 낙하 충돌 시뮬레이션을 실시하였다. 시뮬레이션결과를 비교 분석하여 최적 적층 단면을 도출하였다.

• 한국방재학회 논문집
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• 제8권3호
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• pp.67-75
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• 2008

본 논문은 형강을 이용한 강-콘크리트 합성복공판 기술개발에 관한 것이다. 기존의 롤포밍 단면을 배제하고 형강을 이용하여 효율적인 강합성 단면을 구성함으로써 제작성과 경제성을 확보하고, 전단연결재의 개선을 통해 합성성능 뿐만 아니라 차후 콘크리트와 강재의 분리에 용이한 구조를 개발하였다. 성능검증 실험결과 기존의 전단연결재만으로는 강재와 콘크리트의 합성거동을 이루는데 한계가 있음을 확인하였다. 나아가 개발 복공판은 설계하중대비 5배 이상의 극한 내하력을 확보하고 있으며, 200만회 피로성능시험에 대해서도 손상이 거의 발생하지 않으며 우수한 구조성능을 나타냈다. 따라서, 형강을 이용한 합성단면 구성을 통해 구조성능 확보뿐만 아니라 기존 합성복공판 대비 약 27% 정도의 강재량 감소가 가능함을 확인하였다.

• Steel and Composite Structures
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• 제12권1호
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• pp.13-29
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• 2012

This paper is an experimental study on the behavior of vertical shear link in normal (steel section with and without stiffener) and composite (steel section with concrete located at the area limited to web and flanges of the section) configurations. This study is mainly aimed to perceive failure mechanism, collect laboratory data, and consider the effect of number of transverse reinforcements on strength and ductility of composite vertical links. There have been four specimens selected for examining the effects of different details. The first specimen was an I section with no stiffener, the second composed of I section with stiffeners provided according to AISC 2005. The third and fourth specimens were composed of I sections with reinforced concrete located at the area between its flanges and web. The tests carried out were of quasi-static type and conducted on full scale specimens. Experimental findings show remarkable increase in shear capacity and ductility of the composite links as compared to the normal specimens.

• 한국소음진동공학회논문집
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• 제20권6호
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• pp.583-592
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• 2010

Equations of motion of thin-walled composite H-type cross-section beams exposed to concentrated harmonic and non-harmonic time-dependent external excitations, incorporating a number of nonclassical effects of transverse shear, primary and secondary warping, and anisotropy of constituent materials are derived. The forced vibration response characteristics of a composite H-type cross-section beam exhibiting the circumferentially asymmetric stiffness(CAS) configuration are exploited in connection with the structural bending-torsion coupling resulting from directional properties of fiber reinforced composite materials.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.185-186
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• 2021

In Korea, many buildings are built with underground spaces and cast-in-place pile method is mostly applied in the temporary retaining walls for the underground space construction. A H-shaped steel section is generally embedded in the soldier pile in the C.I.P method. In this study, a new and economical section with high strength steel replacing the H-shaped section was proposed and its flexural capacity was evaluated experimentally. The new section is the concrete-filled composite section with pentagonal thin plate and thick flange plate. Test results showed that the proposed section has an excellent flexural strength and ductility.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.641-646
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• 2002

FRP-concrete composite slab is consisted of brittle materials and then shows brittle failure mechanism. This study suggests a new design approach that FRP-concrete composite slab leads to ductile failure, and investigates their failure behaviors for two types of section by numerical analysis. Box-type section is higher than I-type section in load capacity to required FRP quantity. Each section was designed so that the strain of FRP plate is 50% to its ultimate strain on initiation of concrete crushing, and it is verified that displacement ductility is more than two. Ductility capacity can be improved by reducing the strain of FRP on initiation of concrete crushing, but as the strain of FRP is reduced load capacity to required FRP quantity is also reduced. Therefore section optimization study is needed considering safety and economical efficiency.