• 콘크리트학회논문집
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• 제13권4호
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• pp.321-328
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• 2001

본 연구는 인장력을 받는 스터드 볼트 접합부에서 주근과 전단보강근이 스터드 볼트의 인장거동에 미치는 영향을 내력과 변형 면에서 검토한 것이다. 주근과 전단보강근이 스터드 볼트 접합부에 미치는 영향을 검토하기 위하여 8개의 실험체를 제작하여 연구하였다. 실험은 주근과 전단보강근량의 각기 다른 5개의 실험체와 접합상세 개발을 위한 3개의 실험체로 구성되었다. 실험결과를 통해서 주근은 스터드 볼트 접합부의 인장내력 상승에 효과가 있는 것으로 나타났으며, 전단보강근의 증가는 최대 내력이후 급격한 취성파괴방지에 효과가 있음을 보여주었다. C형(폐쇄형, 개방형)보강근, U형 보강근을 사용한 접합부는 스터드 볼트 전합부의 연성거동에 효과가 있음을 보여주었다. 기존실험결과 분석으로부터 CCD식에 의해 인장을 받는 접합부를 설계시, 강도감소계수를 0.75 ø로 사용할 것을 제시한다.

• Steel and Composite Structures
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• 제39권5호
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• pp.529-542
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• 2021

Shear connectors are required to build composite (concrete and steel) beams. They are placed at the interface of concrete and steel to transfer shear and normal forces between two structural components. Such composite beams are sensitive to provide structural integrity when exposed to fire as they loss strength, stiffness, and ductility at elevated temperature. The present study is designed to investigate the shear resistance and the failure modes of the headed stud shear connectors at fire exposure and post-fire exposure. The study includes ordinary concrete and concrete with carbon nanotubes (CNTs) to build composite (concrete-steel) beams with structural steel. Experimental push tests were conducted on composite beams at ambient and elevated temperatures, such as 200, 400 & 600℃. Moreover, push tests were performed on the composite beams after being exposed to 200, 400 & 600℃. Push test results illustrated the reduction of ultimate shear capacity and stiffness of headed stud shear connectors as the temperature increased. Although similar values of ultimate shear were obtained for the headed stud connectors in both ordinary and CNT concrete, the CNT modified concrete reduced the concrete spalling and cracking compared to ordinary concrete and was observed to be effective at temperatures greater than 400℃. All specimens showed a lower shear resistance at fire exposures compared to the corresponding post-fire exposures. Moreover, numerical simulation by Finite Element (FE) analyses were carried out at ambient temperature and at fire conditions. The FE analysis results show a good agreement with the experimental results. In the experimental studies, failure of all specimens occurred due to shear failure of headed stud, which was later validated by FE analyses using ABAQUS.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.124-127
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• 2009

In this paper, a longitudinal die insert fracture which occurred during cold forging of a high strength ball-stud with a sound die design nearly optimized empirically for relatively low strength material of SCM435 is introduced and the reason is revealed. A comparative study between SCM435 and ESW105 is quantitatively made using a thermoelastic finite element method for die structural analysis coupled with a forging simulator theoretically based on a rigid-plastic finite element method. It has been shown that the longitudinal die insert fracture caused from non-optimized value of shrink fit, emphasizing that the die optimal design is inevitable for cold forging of high strength materials.

• 비파괴검사학회지
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• 제9권1호
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• pp.106-110
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• 1989

Bolting degradation problems in primary coolant pressure boundary applications have become a major concern in the nuclear industry. In the bolts concerned, the failure mechanism was either corrosion wastage(loss of bolt diameter) or stress-corrosion cracking.(3) Here the manual ultrasonic testing of RPV(Reactor Pressure Vessel) and RCP(Reactor Coolant Pump) stud has been performed. But it is difficult to detect indications because examiner can not exactly control the rotation angle and can not distinguish the indication from signals of bolt. In many cases, the critical sizes of damage depth are very small(1-2 mm order). At critical size, the crack tends to propagatecompletly through the bolt under stress, Resulting in total fracture.(3) Automatic stud scanner for studs(bolts) was developed because the precise measurement of bolt diameter is required in this circumstance. By use of this scanner, the rotation angle of probe was exactly controlled and the exposure time of radiations was reduced.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1091-1096
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• 2001

Generally, in a steel girder and the concrete slab act as a composite structure, the connectors must have adequate strength and stiffness. If there are no horizontal or vertical separations at the interface, the connectors are described as rigid, and complete interaction can be said to exist under these idealized circumstances. In previous study, it was considered that the strength of stud is affected by the stud diameter, height of stud and compressive strength of concrete. The differences between previous study and this study are variables, which are shank diameter of shear connector, the spacing of shear connector, the size of specimen and the row of shear connector. So this paper, as a study on the strength of shear connector with the spacing of shear connector, size of specimen (block-out size), row of shear connector and shank diameter of shear connector resulted from the push-out specimen are conducted with ABAQUS program. It is to investigate the effects of characteristics of these factors. The load-slip relations obtained from the experiments are compared with those of analyses. From these results, the trends of stress are stress estimated and compared with push-out test.

• Structural Engineering and Mechanics
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• 제38권1호
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• pp.99-123
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• 2011

Brick veneer over steel stud backup wall is lighter and easier to construct compared to brick veneer over concrete masonry backup wall. However, due to the relatively low stiffness of the steel stud backup, the brick veneer tends to crack under wind load. This paper briefly introduces a new panelized brick veneer with steel frame backup wall system that is developed to potentially address this problem. The experimental study of the performance of this system under simulated wind loading is discussed in detail. The test setup details and the test specimens are introduced, results of major interests are presented, and performance of the new system is evaluated based on the test results.

• Steel and Composite Structures
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• 제2권5호
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• pp.355-378
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• 2002

Use of composite steel construction with precast hollow core slabs is now popular in the UK, but the present knowledge in shear capacity of the headed shear studs for this type of composite construction is very limited. Currently, all the information is based on the results obtained from experimental push-off tests. A finite element model to simulate the behaviour of headed stud shear connection in composite beam with precast hollow core slabs is described. The model is based on finite element method and takes into account the linear and non-linear behaviour of all the materials. The model has been validated against the test results, for which the accuracy of the model used is demonstrated. Parametric studies showing the effect of the change in transverse gap size, transverse reinforcement diameter and in-situ concrete strength on the shear connection capacity are presented.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.341-344
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• 2006

Finite element analysis and verification experiments were performed in order to find cause of defects such as folding and improper radius around the root area of the thread rolled stud bolts. Thread rolling experiments under several conditions were also carried out to understand the effect of process parameters, such as the rotation speed of the dies and the hardness of the work pieces, on the product quality. Folding defects at the top of thread are attributed to the higher hardness of the work piece and higher rotation speed of the rolling die. It was also found that the radius of screw mainly determined by the radius of the die.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.535-540
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• 2000

When the stud connection is considered as pin joint in the practical design, it is required to have high deformability. The rotational capacity as well as moment of the connection are evaluated through experimental works. Considered in the test are the reinforcement ratios of concrete member, the magnitude of axial force and connection details. It is shown that the stud connection has some quantity of moment capacity buy on the other hand it has low deformability. The strength and deformability of the connection depend on the axial force and reinforcements around the studs. The strength and ductility of the connection ate increased by using closed C-type.

• 교육녹색환경연구
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• 제10권2호
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• pp.1-7
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• 2011

An experimental study to evaluate structural capacity of an embedded plate connected with prestressed concrete beam was performed. Embedded steel plates and prestressed concrete beam were connected with stud-bolts at the ends of concrete beam specimens. About 1,000 kN concentrated load was applied at 450mm away from the end of beam specimen. A 3,000 kN capacity static Oil-jack was used to direct concentrated load. The maximum strain of stud-bolt recorded $90{\times}10^{-6}$(mm/mm) and wide width cracks were not founded. Any falling failures of concrete and large deformations were not founded either between steel plate and prestressed concrete specimen. As a result, construction performance can be improved using this embedded steel plate connection system apply to large space educational facilities.