• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.93-93
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• 2010

We developed friction welded bimetallic sleeve for 220kV aluminum conductor XLPE cable. Not only friction welded bimetallic sleeve for Termination(EB-A, EB-G) but also friction welded sleeve for Joint of Al to Cu conductor was developed regardless of this project. Generally, friction welded sleeve used to connect Al conductor cable to Cu conductor cable and used for improvement of mechanical property of terminal by offer the copper side of friction welded bimetallic sleeve at the Termination. Connection method for Al-Cu conductor has mainly used friction welding at the solid state, because it is difficult to connect by using conventional welding method. this investigation introduces development of friction welded bimetallic sleeve by friction welding and test result of 220kV Al conductor XLPE cable and accessories using friction welded sleeve.

• 한국정밀공학회지
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• 제28권3호
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• pp.357-362
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• 2011

Air springs are prevalently used as suspension in train. However, air springs are seldom used in automobiles where they improve stability and comfort by enhancing the impact-relief, breaking, and cornering performance. Thus, this study proposed a new method to analyze air springs and obtained some reliable design parameter which can be utilized in vehicle suspension system in contrast to conventional method. Among air spring types of suspension, this study focused on sleeve type of air spring as an analysis model since it has potential for ameliorating the quality of automobiles, specifically in its stability and comfort improvement by decreasing the shock through rubber sleeve. As a methodology, this study used MARC, as a nonlinear finite element analysis program, in order to find out maximum stress and maximum strain depending on reinforcement cord's angle variation in sleeves. The properties were found through uniaxial tension and pure shear test, and they were developed using Ogden Foam which is an input program of MARC. As a result, the internal maximum stresses and deformation according to the changes of cord angle are obtained. Also, the results showed that the Young's modulus becomes smaller, then maximum stresses decrease. It is believed that these studies can be contributed in automobile suspension system.

• 한국가스학회지
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• 제18권2호
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• pp.62-68
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• 2014

도시가스 배관의 현행 보수 방법으로는 육성 용접, 슬리브 용접과 같은 용접을 이용한 방법 이외에 탄소 섬유나 유리 섬유 복합 재료를 사용한 보수 방법이 해외에서 사용되고 있다. 우리 나라의 경우도 도시가스 배관 안전관리의 중요성이 대두되면서 자체보수규정을 마련할 필요성이 있다. 해외의 사례로서 이미 연구가 상당부분 이루어진 용접에 의한 보수 방법이 아닌 비교적 새로운 보수 방법인 복합재로 보수 방법에 대한 연구가 필요한 시점이다. 본 논문에서는 복합재료 보수배관의 안정성 평가의 기본 단계로서 탄소 섬유 복합재료를 사용하여 보수한 가스 배관의 유한 요소법을 이용한 구조 해석을 수행하였고 결과에 대해 고찰해 보았다.

• 한국의류산업학회지
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• 제18권5호
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• pp.637-646
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• 2016

The goal of this study is to provide basic data on developing circular knit basic pattern for women in their 20's. Production conditions of circular knit product pattern making among domestic women's apparel industry was researched, and collected data on sizes and ease amounts from woven and circular knit pattern were compared and analyzed. According to the result of the survey, product measurements adjusted to the actual body size fit for the brand's image were used, and the common problem among manufacturers and consumers regarding circular knit products turned out to be change in size and form due to stretching. For the basic pattern of circular knit, stretching quality was reflected in the woven basic pattern based on plain stitch(single knit) and then dart was removed and ease amount was reduced. The result of looking into size and ease amount about woven and circular knit torso & sleeve block shows that there is a significant difference among chest circumference, hip circumference, bi-shoulder length, interscye back, interscye front, scye depth, upper arm circumference and wrist circumference, and it was clear that circumference and width on the areas around the wrist tended to fit around the body more when circular knit was used instead of woven fabric.

• Journal of Welding and Joining
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• 제33권1호
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• pp.87-93
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• 2015

This study was performed to develop repair technology for J-Groove dissimilar metal weld of pressurizer heater sleeve in nuclear power plants. Pad, J-Groove automatic welding and mechanical machining equipments to develop repair technology using 'Half Nozzle Repair' were designed and manufactured. To obtain the optimum welding process parameters during Pad temperbead overlay welding, several welding experiments using Taguchi method were conducted. Weldability of Pad overlay weld specimens was estimated by PT/RT test, FE-SEM, EDS and Vickers hardness test. Also, J-Groove welding to adjust weld shape conditions requiring in ASME Code was carried out and its integrity of weld specimens was evaluated through PT/RT test and optical microscope. Consequently, it was revealed that Pad and J-Groove overlay welding for dissimilar metal weld of pressurizer heater sleeve could be possible to meet Code standard without weld defect.

• Elastomers and Composites
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• 제38권4호
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• pp.334-341
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• 2003

부싱은 차체로 전달되는 하중을 줄여주는 역할을 하는 자동차 현가장치의 부품으로 바깥쪽 슬리브와 안쪽의 축 사이에서 가운데가 비어있는 실린더의 형상을 가진다. 축에 작용되는 하중과 부싱의 상대 변위는 비선형 점탄성 성질을 나타내며, 부싱에서 힘과 변위의 관계는 다물체 동역학 시뮬레이션에 중요하다. 비선형 점탄성 축방향모드에 대하여 힘과 변위와의 직접관계식인 ??킨-라저스 모델을 리아니스 모델로부터 유도하였으며, 사인함수의 변위를 ??킨-라저스 모델에 적용하여 주파수와 변위의 변화가 비선형 점탄성 부싱 모델에 미치는 영향에 대하여 알아보았다.

• 연구논문집
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• 통권28호
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• pp.73-87
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• 1998

A pneumatic control system of compressed air as a working fluid has a variety of advantages such as low price, high respondence, non-explosion and good control performance and thus has many applications in the field of automobile, electronic and semiconductor industry. However, it has a difficulty in contolling a precise position due to quick response of system and compressibility of working fluid and. in particular, shock stress may occur due to an external load, resulting in fracture of a cylinder cap unless cushion device is equipped in the linear actuator. To avoid this, a cushion device should be installed for damping effect of the external load and the supply pressure as well as for decreasing shock stress and vibration caused by high speed rotation. Previous studies include dimensionless analyses and computer simulations of cushion capability and experiments of horizontally-mounted cylinder performances. A new attempt is experimentally made in this study using a vertically-mounted cylinder under an operation condition of 4, 5 and 6 (bar) as supply pressure and 40, 70 and 100 (kgf) as external load. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion characteristics was also revealed in the meter-in circuit.

• 한국주조공학회지
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• 제31권4호
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• pp.205-211
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• 2011

Al-Si alloys have been steadily used as a potential material for the achievement of an efficient weight reduction in the automobile and aerospace industries due to its excellent castability and high strength-to-weight ratio. In this study, riser effect and mechanical properties were investigated according to the size of the sleeve. In addition, the effects of riser size on mechanical properties of castings were investigated. On the other hand flow and solidification process were simulated with a hybrid FDM/FEM package named ZCast. As a result, results of simulation and experiments were comparable regarding to the yield strength, tensile strength, elongation and hardness of casting. It proves the reliability of the simulation. It is expected that the proper size of riser can improve the recycling rate of metallic materials and reduce the cost of casting.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.727-728
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• 2007

송전선로의 송전능력은 크게 연속허용용량과 단시간 허용 용량으로 구분되는데, 단시간 허용용량은 전선의 수명에 영향을 미치므로 이에 대한 명확한 기준과 관리가 필요하다. 단시간 운영기준의 정립을 위해서는 송전선 도체의 과부하 시간에 따른 도체수명평가 기술이 필요하며, 선로의 취약지점인 접속개소에 대한 열특성 분석이 수반되어져야 한다. 본 논문에서는 과부하시나 돌발적 위급상황시 송전선의 단시간 운영과 관련된 도체 및 접속개소의 열특성을 파악하기 위하여 전선 및 접속슬리브의 고온인장강도시험과 가속열화시험을 통해 단시간 허용 온도특성을 살펴보고, 그 결과에 대하여 분석 및 검토한다. 분석 및 검토결과는 ACSR계 도체의 단시간허용온도가 현행의 100$^{\circ}C$에서 120$^{\circ}C$ 이상으로 상향조정이 가능함을 보여준다.

• 한국재료학회지
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• 제16권11호
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• pp.698-704
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• 2006

In this study, the effect of chill layers occurred in shot sleeve on the molten metal filling was analyzed through computer simulation. The behavior of chill layers with temperature variation of shot sleeve set from 200 to $280^{\circ}C$ was also investigated. The simulation results showed the chill layers set in the in-gates during the injection process change the main filling direction and cause turbulent flow pattern, resulting in porosities inside the castings. The amount of chill layers with the increasing temperature of shot sleeve was considerably reduced. Particularly, at the setting temperature of $280^{\circ}C$ by heat control unit, the biggest reduction in chill layers, excellent trimmed surface and the highest density were achieved, suggesting that as the optimal sleeve condition in aluminum high pressure diecasting, especially for highly complex parts like valve body.