• 대한토목학회논문집
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• 제33권3호
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• pp.1243-1251
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• 2013

본 연구의 목적은 텐션클램프의 초기 체결력이 급곡선 궤도용 탄성레일체결장치의 성능에 미치는 영향을 검토함에 있다. 이를 위해 본 연구에서는 탄성레일체결장치의 구성품 중 텐션클램프의 거동을 평가하기 위해 초기 체결력의 변화와 횡압의 증가를 고려한 실내시험, 현장측정 및 수치해석을 수행하였다. 수치해석 및 실험결과, 초기 체결력의 감소는 텐션클램프에 도입되는 초기 압축응력의 감소로 나타났다. 또한 텐션클램프의 압축응력은 급곡선 궤도에서 발생하는 횡압의 작용에 따라 인장응력으로 변환되는 것으로 나타났다. 따라서 초기 체결력에 의해 텐션클램프에 도입된 압축응력은 외력에 따른 발생 인장응력 저감을 위한 보강력으로 작용하는 것으로 분석되어, 탄성레일체결장치의 장기 내구성능 확보와 안정적인 거동을 유지하기 위해서는 적정 초기 체결력의 확보가 중요한 것으로 나타났다.

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8812-8819
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• 2015

콘크리트 궤도 건설의 증가로 인한 레일 체결장치의 중요성이 커지고 있는 상황에서 최근 레일 체결장치의 부속품인 텐션클램프가 절손되는 사고가 발생되었다. 이는 현장상태, 운영기관, 열차운행조건 및 빈도 등 다양한 요인에 의한 것으로 텐션클램프의 거동관련 연구가 필요하다. 본 논문에서는 실내실험 및 유한요소해석을 통해 텐션클램프의 역학적 거동을 분석하였다. 실내실험을 수행하여 텐션클램프 체결력에 따른 응력 및 변위를 도출하고 이를 유한요소해석 결과와의 비교를 통해 해석 모델을 검증하였다. 또한 검증된 모델을 적용하여 열차 하중에 따른 텐션클램프의 변형과 응력을 도출하고, 응력 분석을 통해 텐션클램프의 피로에 대한 취약도를 파악하였다.

• 문화기술의 융합
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• 제8권3호
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• pp.265-270
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• 2022

본 연구는 콘크리트 궤도용 탄성레일체결장치(System 300-1)의 손상취약부에 관한 실험 및 해석적 연구이다. 콘크리트 궤도에서 탄성레일체결장치는 열차주행 시 레일과 침목을 결속하는 핵심 궤도구성품이다. 레일체결장치 구성품 중 방진패드와 텐션 클램프(Tension Clamp)는 압축력과 부상력에 대응하며 상시 변형이 발생되는 피로부재이다. 본 연구에서는 동일구간의 운행선에서 6년, 11년, 16년 동안 사용된 탄성레일체결장치를 채취하여 사용년수에 따른 텐션 클램프의 잔류변형 특성을 분석하였다. 또한 수치해석을 바탕으로 주요 구성품별 거동메커니즘을 분석하고 손상취약부를 도출하였다. 본 연구에서 수행한 수치해석을 통해 체결력 도입부터 외력 작용에 따른 텐션 클램프 각부의 응력(변형율)을 분석하여 텐션 클램프의 손상취약부를 도출하였다.

• 한국정밀공학회지
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• 제28권2호
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• pp.193-201
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• 2011

Clamp type transferring mechanism for package substrate's wet processes was newly developed instead of conventional roller type transferring mechanism. Clamp type transferring mechanism has the advantages of reducing the panel deflection and of minimizing the contact problem between the panel and the transferring mechanism. Individual clamp of the mechanism has two distinct mechanical functions which are perfectly fixing a panel during the transferring and generating adequate tension for the panel. To determine the mechanical parameters of the clamp, panel deflection simulation was conducted and the result was verified by the panel deflection measurement. Also, fixing angle of a clamp could be determined by the free body force analysis of individual clamp. Finally clamp type transferring mechanism was actually manufactured and the transferring performance was verified during the water spraying condition of the package substrate's wet processes.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.909-914
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• 2004

This study investigate the cause analysis on fracture of dropper clamp in catenary system. Dropper clamp is using as a holder between messenger wire and contact wire in catenary system. To analyze the cause analysis on fracture of dropper clamp, we have conducted experiment such as tension withstand strength test, holding strength test of a new products, SEM and EDX of field fractured specimens.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.219-225
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• 2018

In this paper, for the testing of tensile strength of dead-end clamp used in transmission line, resulting values were estimated by designing and producing the horizontal version of widely-used vertical tensile tester. Tensile strength test of dead-end clamp for transmission line is essential for quality test of products. Moreover, tensile tester is an equipment that requires high level of reliability which needs to be examined through sampling tests commensurate with total inspection. Frames of tensile tester were made up of H-beams so that it can endure more than 20 [tons] of load capability and the test was implemented for 60[seconds] applying five types of tension. In consequence, the tester could withstand up to 21,600[kg] of weight as well as all types of tension. This newly developed horizontal tensile tester can be utilized in figuring out properties of various materials by estimating tensile strength of materials such as metal, rubber and fiber.

• International Journal of Contents
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• 제9권1호
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• pp.38-41
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• 2013

The clamp meter maintains electric safety as a non-invasive method while measuring the absolute value of tube current with it has been recently developed for an X-ray high-tension cable. Especially this can show high accuracy at short X-ray exposure time. Considering such a condition, this study is to evaluate the feasibility of a clamp meter in measuring X-ray tube current by taking the measurements and comparing with those of the Dynalyzer III which has been considered as a standard measuring device. From measuring the tube current accuracy depending on changes in tube voltage and exposure time, the clamp meter showed higher accuracy rate which was -1.3~4.2% difference. Thus clamp meter can be used for clinical radiologists who are not familiar electric circuit to manage X-ray devices easily and correctly in the future.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1444-1452
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• 2011

At present, Kyungbu high-speed railway is operated with 300km/h, Honam high-speed railway is being constructed with 350km/h, and the development for the overhead contact line system is to be conducted for the next-generation high-speed railway with the speed of 400km/h. It is necessary to set up the specification and criteria for the key parts such as dropper, termination clamp and tension insulator for the 400km/h railway line. In this paper, the specification and the criteria for dropper, termination clamp and tension insulator has been reviewed and proposed in order to secure long-term reliability and stability under the maximum speed of 400km/h. Also, the specification, criteria and international standards for 300km/h class and 350km/h class railway line system and the international standards related with the insulators have been reviewed, compared and analysed.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1399-1403
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• 1992

The evaluation of the effectivess of ongoing cardiopulmonary resucitation efforts is dependent on the commonly used methods, such as the presence of femoral or carotid artery pulsations, arterial blood gas determinations, peripheral arterial pressure and intracardiac pressure monitoring. But recent studies suggest that end-tidal carbon dioxide tension serves as a non-invasive measurement of pulmonary blood flow and therefore cardiac output under constant ventilation. A prospective clinical study was done to determine whether end-tidal carbon dioxide monitoring in open heart surgery under cardiopulmonary bypass could be used as a prognostic indicator of bypass weaning. We monitored end-tidal PCO2 values continuously during cardiopulmonary bypass in 30 patients. "Ohmeda 5210 CO-2 monitor" under infrared absorption method were incorperated into the ventilator circuit by means of a side point adaptor between endotracheal tube and ventilator tubing. 18 patients[Group I ] were res-ucitated from partial bypass followed by aorta cross clamp off and 12 patients[Group II ] from aorta cross clamp off followed by partial bypass. But there was no difference between two groups[p>0.05]. The value of end-tidal carbon dioxide tension during ventricular fibrillation or nearly arrest state was 6.6$\pm$2.9 mmHg, and at the time of spontaneous beating was 19.3$\pm$5.6 mmHg[Mean$\pm$Standard deviation], In conclusion end-tidal carbon dioxide tension monitoring provides clinically useful, continous, noninvasive and supplementary prognostic indicator during cardiopulmonary bypass weaning procedures.rocedures.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.527-535
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• 2015

As a new technical approach, a hydraulic and magnetic clamp device was attempted to realize a magnetic clamp crane system that uses 8 simultaneously actuating individual hydraulic cylinders. Through this approach, a Sr type of ferritic permanent magnet ($SrO{\cdot}6Fe_2O_3$), not the previously employed electro-magnet, was utilized for the purpose of lifting and transporting the heavy weighted and oversized curved steel plates used for manufacturing the ships. This study is aimed at manufacturing and developing the hydraulic magnetic clamp prototype, which is composed of three main parts - the base frame, cylinder joint, and magnet joint - in order to safely transport such curved steel plates. Furthermore, this research was pursued to conduct a performance evaluation as to the prototype manufacture and acquire the planned quantity value and the development purpose items. The most significant item for a performance evaluation was estimated for the magnetic adhesive force (G) and in this process, a ferritic permanent magnet (Sr type) with 3700~4000 G of residual induction (Br) and 2640/2770 Oe of coercive force (Hc) was utilized. In addition, other relevant items such as hoist tension (kN), transportation time (sec), and the applied load (Kgf) exerted on the hydraulic cylinders were also evaluated in order to acquire the optimum quantity value. As a result of the evaluation, the relevant device turned out to be suitable for safely transporting the curved steel plates.