• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.375-381
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• 2008

This paper deals with the shear capacity of corrugated rib as the shear connector in composite structures. Corrugated rib is modified as perfobond rib shear connector type to evaluate the shear capacity. A total 12 push-out specimens with stud, perfobond rib, and corrugated rib connector were fabricated. Then, the influences of hole-crossing bars, concrete dowel, depth of corrugated panel and height of rib on the shear capacity were evaluated experimentally. As the results of these tests, the failure mechanisms of corrugated rib and perfobond rib specimens were associated with the bearing failure of the concrete slabs, but the failure of weld zone did not occur. The shear capacity of corrugated rib specimens improved as high to 96% compared to the perfobond rib shear connectors. Also, the hole-crossing bars were effective on the improvement of concrete dowel action, and consequently, shear capacity increased by 48%. It was also proven that the increment of the depth of corrugated panel and the height of rib increased the concrete bearing resistance, therefore increasing the shear capacity.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.207-212
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• 2013

To investigate the possibility of using artificial means for the control of shear layers in swirl jets, a shear excitation device is introduced. The device consists of co-centric dual nozzles with internal lobes (i.e., convex surfaces) of small height to induce disturbance. The number of convexities can be varied to produce the various modes in azimuthal direction. The acquired velocity data of the swirling jets, with and without the lobes, are numerically simulated in 2-D contour plots and 3-D particle trace plots. The results are compared with the baseline (i.e., no excitation case) at various excitation modes. Conclusively it is observed that the artificial excitation method is effective in the control of the vortical structure in swirling jets.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.367-375
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• 2014

Recently the use of concrete post-installed set anchors has been increasing because this constructing method is flexible and easy to attach or fix structural members when we repair, reinforce, or remodel a concrete structures. Depending on the shear strength of steel, the strength of concrete, edge distance and anchor interval, etc, the anchor loaded in shearing exhibits various failure modes such as steel failure, concrete failure, concrete pryout. In this study, the objective is to investigate the effects of the variations like anchor embedment depth, anchor interval, edge distance and concrete strength on the shear failure behavior of post-installed concrete set anchor embedded in concrete. The results of embedment depth experiments show that concrete strength has much effection on the shallow embedment depth. Steel failure occur to all results of the anchor interval experiments, but concrete is failed when edge distance experiments that less than the embedment depth. Through the comparision of the same parameters experiments results show that as strong as concrete strength are the displacement results are small.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5566-5571
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• 2012

Block shear failure is one of limit states, and demands great caution in designing the tension member or connection joint of steel structures. From many studies and design specification, it is shown that the effect of the bolted connection type on the block shear failure was not considered. In order to investigate the effect of the bolted connection type(bearing type connection and slip critical connection) on the mode/strength of the block shear failure, tensile experiment is conducted in this study. Differences about the failure mode according to the design specification, bearing type connection, and slip critical connection are proposed from the analysis of test results. The variation of the block shear failure strength due to the frictional force in the slip critical connection is also investigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.4 s.70
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• pp.361-372
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• 2005

In the previous study(Kim 등, 2004), the finite element method was used for the vortical vibration analysis of suspension bridge with the effects of the shear deformation and the rotary inertia under moving load considering the bridge-vehicle interaction. The purpose of this study is to investigate the effect of an eccentric vehicle and shear deformation. So we firstly performs the eigenvalue analysis for the free vortical and the torsional vibration of suspension bridges using FEM analysis. Next the equations of motion considering interaction between suspension bridges and vehicles/trains are derived using the mode superposition method. And then dynamic analysis was performed using the Newmark method. Finally through the numerical examples, the dynamic responses of bridges are investigated according to the proposed procedure.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.33-42
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• 1999

In the present study, crack initiation criteria, static failure and tensile mode fatigue behavior for a rail steel are evaluated to assure the railway vehicle's safety. The transverse fissure, which is the most critical damage in the rail, is initiated by the maximum shear stress and its location is subsurface. In addition, the possibility of transition from the shear mode to the mixed mode increases with increasing the length of subsurface crack. Because of the brittleness by the welding, the fracture toughness of the welded part is lower than of the base metal. For low ${\Delta}K$, the stage II fatigue crack growth rates of the welded part is slower than of the base metal but, for high ${\Delta}K$, this different behavior for fatigue crack growth rate is nearly diminished. These trends are more remarkable for low stress ratio, R=0.1. It is believed that this behavior is caused by the change of the microstructure which that of the welded part is coarser than of base metal.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.760-763
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• 2011

본 논문의 목적은 효율적인 3절점 판 유한요소를 개발하는 것이다. Hellinger-Reissner 범함수에 근거한 혼합정식화(mixed formulation)를 사용한다. 잠김현상을 일으키는 전단변형률장을 독립적으로 분리한 후, MITC(Mixed Interpolation of Tensorial Components)방법을 이용하여 대체전단변형률장(assumed transverse shear strain field)을 구성한다. 추가적으로 회전된 반변기저벡터(contravariant base vector)로 정의된 근사전단변형률장(approximated transverse shear strain field)에 미지수(unknowns)를 도입하여 혼합정식화를 완성시키고 정적응축(static condensation)을 통해 최종 강성행렬을 구성한다. 거짓영에너지모드시험(spurious zero energy mode test), 조각시험(patch test), 등방성시험(isotropic test) 등을 실시하였으며, 4변 완전구속 정사각형 판 구조물과 60도 기울어진 단순지지 판 구조물 등 예제들을 해석하여 MITC3판 유한요소와 수렴성능을 비교하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.4
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• pp.661-669
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• 1999

이 논문은 탄성지반위에 놓인 원호형 곡선보의 자유진동에 관한 연구이다. 회전관성 및 전단변형을 고려하여 두 개의 매개변수로 표현되는 탄성지반위에 놓인 원호형 곡선보의 자유진동을 지배하는 미분방정식을 유도하고, 이를 수치적분기법과 시행착오적 행렬값탐사법이 결합된 수치해석기법으로 해석하였다. 회전-회전, 회전-고정 및 고정-고정의 단부조건을 갖는 곡선보의 최저차모드 3개의 고유진동수를 산출하였다. 곡선보의 수평높이 지간길이비, Winkler 지반계수, 전단지반계수에 따른 고유진동수 변화를 분석하였으며, 회전관성 및 전단변형의 영향을 고찰하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.3
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• pp.107-115
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• 2000

충적지반에 건설된 원형 단면을 갖는 터널은 지진시에 지반의 전단 변형의 영향을 받아 좌우교차로 경사진 타원형상의 변형을 반복한다. 본 논문에서는 이 특별한 진동모드를 이용하여 지반-터널계의 상호작용 및 면진 효과가 검토되었다. 지반과 터널의 경계가 완전히 결합되어 있는 경우에 대한 지반 -터널계의 상호작용 효과 및 지하 구조물의 지진피해를 줄이는 한가지 방법으로써 터널 주위를 면진재로 피복하는 방법에 대한 면진효과가 토론되었다. 그 결과 면진재의 포아송비를 작게 하거나 지반과 면진재의 전단탄성계수의 비를 증가시킴으로서 면진 효가가 증가함을 알 수 있었다.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.405-416
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• 2006

In composite girders with steel embedded in concrete as preflex beams, horseshoe connectors and bar connectors are commonly used to achieve composite action. Considering the requirements on the concrete cover in the thin concrete part surrounding a steel member, it has limitations with respect to the use of stud shear connectors, and significant bond and friction resistance can be generated. High horizontal shear strength between the casing concrete and the steel section is needed to introduce prestress to the concrete section in the form of preflex beams.In this paper, experiments on the evaluation of the static strength of horseshoe connectors and bar connectors were conducted and the effects of bonds were also considered. Based on the test results, current design codes were estimated and more general design guidelines that consider the design concept of Eurocode were proposed for the connectors. A strength evaluation according to failure and compared with the test results.