• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1755-1756
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• 2008

본 연구는 이동하면서 트롤리선 가설하는 작업로봇에서 가선 트롤리선에 대한 장력제어 방법이 제안되었다. 비선형 와이어 모델, AC 전동기를 이용한 장력발생 시스템 및 와이어 장력 방정식 에 기초하여 장력제어 시스템이 로드셀에 의한 장력 검출로 설계되고 실행되었다. 장력응답은 실험에서 만족하게 장력의 조절하는 것으로 보인다. 제안한 장력제어 시스템은 시뮬레이션과 실험을 통하여 그 결과가 유효함을 증명하였다.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2001.11a
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• pp.43-47
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• 2001

This paper presents a study of the uniform metal droplet generation using laser. The theoretical model, based on the variational principle instead of solving the Wavier-Stokes equation with moving boundaries, is developed. Our model is considered the Young-Laplace equation and force equilibrium conditions. Surface tension coefficient is determined under the statical condition with induced differential equation by using experimental result. In case of dynamic vibration, metal droplet shape and critical detaching volume are predicted by recalculating of proposed model. The simulation result revealed that the developed model could reasonably describe the molten metal droplet behavior on vibration with metal wire.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.116-118
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• 2001

It is important to determine of tower type whether suspension or tension tower in overhead transmission lines. When we select to tower type, we have need to check of swing angle for suspension string sets. And jumper wire of T/L in the strong wind area have to analysis of swing angle in order to clearance or length of tower arms. This paper is summarized the methods to calculate of swing angle for suspension string sets and jumper wires, and is calculated the swing angle. The calculated result have proposed to improved design specifications of overhead transmission line.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.90.2-90.2
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• 2010

흙막이 굴착 및 절취사면의 보강공법으로 많이 적용되고 있는 앵커의 장력을 측정하는 전기저항식 로드셀과 스트레인게이지, 바이브레이팅 와이어 (vibrating wire) 타입의 모니터링 방법은 안전관리를 위한 장기적인 모니터링에 한계를 가지고 있어 이를 개선할 수 있는 방안으로 광섬유 센서를 이용하여 강연선의 변형률을 측정할 수 있는 스마트 텐던이 개발되었다(김재민 등, 2007). 앵커를 구성하는 7연 강연선(텐던)의 중앙케이블에 삽입된 광섬유브래그격자(Fiber Bragg Grating ; FBG)센서는 기존 스트레인게이지 타입에 비해 크기가 작고 내구성이 우수하며 전자기파에 의한 노이즈 발생이 없고 하나의 리드선으로 다중점 측정(multiplexing)이 가능하여 장기모니터링에 효과적인 장점이 있다. 본 연구에서는 FBG센서를 내장한 스마트 텐던을 실대형(Prototype) 앵커(L=11.5m)에 적용하여 현장 인발실험에 의해 시공중 장력 모니터링을 수행하고 로드셀 측정결과와 비교하였고 정착부에 설치된 FBG 센서로부터 앵커의 하중전이 계측을 수행하였다.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.981-986
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• 2002

ACSR of the catenary wires is corrosion degradation progressed by the effect of atmospheric pollution. ACSR which consists of galvanized steel stranded aluminum. The inside of Steel Reinforced is hot-dipped zinc coating steel wire and it takes charge of tension. If ACSR is exposed in atmosphere, the galvanic corrosion is occurred because it is contacted with aluminum. It is occurred the chemical reaction rapidly so that the local a defect is also occurred. If the catenary wires are exposed in atmosphere of pollution conditions, it may cause to reduce the mechanical strength by corrosion degradation and may cause to damage the wires by micro cracks. Accordingly, this study presents the effects of mechanical properties through the corrosion of ACSR.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.140-142
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• 1998

The major part of SMES (Superconducting Magnetic Energy Storage) system consist of the superconducting coil, cryostat and current lead, power converter. The 0.7MJ SMES coil was a design and manufacture by using SMES device that we developed a design code. A SMES coil was wound with high winding tension in order to prevent wire motion from Lorentz force. This paper described optimum design for the SMES coil.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1690-1692
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• 2000

The principle of crimping connection is to produce a compressive connection force between terminal and cores(wire conductor). Compressive connection force is produced by pushing each other on that stress(crimping force) of barrel by restored elastic strain after plastic deformation and the expansion force of cores' elastic stress. And resistance and tension force between terminal and cores are determined according to the condition of compressive connection force. In this study, we've found out that the adaptive height which has maximum tensile force by measuring a tensile force with a height of terminal.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.170-173
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• 2002

The object of this study is to investigate the effect of compounded welding through the AE (Acoustic Emission) characteristics on static tensile test. This study was carried out a SM 490A, high tension steel using the low hydrogen type E4316 of electronic shield metal arc welding and compound wire of $CO_2$gas arc welding. $CO_2$welding, weak in the intensity of HAZ (Heat Affected Zone), can be improved by being combined with coated arc welding, Coated arc welding, weak in the intensity of the bead, can be improved by being combined with $CO_2$welding. Especially, electronic coated arc welding and $CO_2$welding complement the mechanical intensity of HAZ and the bead with each other. So, compounded welding increases the intensity in the special parts and enhances the quality of goods.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.478-483
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• 2006

In this study, as a part of research which is to make 50kg NSI turnout of PC sleeper, the main objective of this study is the optimization of PC sleeper's section, the number of PS tension wire. For this purpose, the finite element analysis was conducted to evaluate the serviceability and the safety of NSI PC sleeper developed. Analytical results showed that PC sleeper adapted in this study satisfied not only serviceability criterion but also safety criterion.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.6
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• pp.368-371
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• 2004

The quench current characteristics of the superconducting solenoids with large diameter were experimentally investigated. Three solenoids with inside diameter of 450mm were fabricated with different tensions and different types of epoxy applications. The quench current of each solenoid was measured according to the various ramping rates of current. The highest quench current was obtained in the solenoid impregnated with epoxy after winding with tension of 20 percents of the yield strength of the superconducting wire. It was found that the quench currents were almost independent of the ramp rate of current. From the results, although the training effect in the solenoid appeared with epoxy impregnation, the quench current of solenoid impregnated with epoxy was higher than that without epoxy impregnated The test results are presented and discussed.