• 한국압력기기공학회 논문집
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• 제19권1호
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• pp.52-59
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• 2023

The welding part of the valve needs immediate action when leakage occurs due to cracks or damage. In order to repair leakage of the welding part, the valve must be separated from the pipe or replaced with a new valve. However, it is difficult to remove the valve while operating the power plant. This study presents a method to remove leakage by precisely processing the gap between the clamp and the incision part within 0.1mm while installed in the pipe system. If the external leakage is removed using a clamp on the welding part without removing the valve during operation, the time and cost required for maintenance can be reduced.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.643-648
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• 2005

Generally, ships have marks of various shapes on outside of the hull. Among them, so called "Draft Mark" indicates the distance from the bottom of the keel to the waterline. Draft marks are used to determine the displacement and other properties of the ship for stability and control purposes. These marks are made up of welding bead or sticking the steel plate on outside of the hull. To improve the confidence level of the ship owner, quality and accuracy of the draft mark is very important. So the automatic mark welding robot is used to enable a high quality and accurate manufacturing line. To improve the system portability, the system is divided into two distinct parts, namely mechanical part and control part. Mechanical part is robust, a lightweight, and easy to dismantle. The control part consists of an in-house developed controller, which is based on embedded Linux. Also, the control part consists of power line communication module to ensure the applicability of the controller in manufacturing line. In this paper, the methodologies of control and configuration of the robot are discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1425-1429
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• 2003

In this study, when structure which is combined by welding is receiving internal pressure, finite element analysis to confirm stability of structure and reliability of welding part is achieved. And we analyze the results. Also, if stability of the structure and reliability of the welding part are not defined, research that look for method to change design to receive stability and reliability is achieved.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.97-99
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• 2007

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.967-968
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• 2012

• 한국생산제조학회지
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• 제19권2호
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• pp.260-266
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• 2010

Today's consumers are looking for emotional design which can fulfill their own potential desire. Emotion varies according to individual circumstance, age, sex, culture, education, profession and so on. Automotive instrument panel design is the most important part of interior design, because it affects the impression of interior design and has the equipments for safety, entertainment and various information. Thus, this study was performed to apply emotional design to automotive instrument panel which is the most important part of automotive interior, and find the best bonding conditions to build instrument panel efficiently by comparing mechanical properties in thermoplastic resin of polyethylene (PE) adhesion. Satisfactory adhesion was executed in ultrasonic welding for the same materials of PE. The best welding conditions were found to be welding time of I second, welding pressure of 250 kPA for PE-PE welding. Dissimilar materials were adhered when adhesion and ultrasonic welding were performed at the same time.

• 한국산학기술학회논문지
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• 제7권5호
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• pp.771-777
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• 2006

최근 자동차에까지 환경친화적인 제품을 의무화하는 규제가 증가하고 있어 전구에 사용되는 납땜을 용접으로 대체하기 위한 연구가 필요하게 되었다. 본 연구에서는 기존의 측면 스폿용접의 문제점을 파악하여 TIG 제살용접공정을 개발하였고 용접시 깨지기 쉬운 유리부의 용접을 위해 세라믹 구조물을 개발하였다. 또한 바닥부 구멍을 메울 수 있도록 기존 바닥부 용가재 용접의 단점을 보완하여 최적 공정 파라미터를 선정하였다. 마지막으로 전구 수명 시험과 내진성 평가를 실시하여 용접된 제동등의 신뢰성을 확인할 수 있었다.

• 수산해양기술연구
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• 제36권4호
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• pp.329-336
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• 2000

정치망 어선에 사용하는 더블 캡스턴 드럼의 용접공정은, 순간적으로 집중투입되는 고온열원에 의해 상당 열응력과 열변형 거동이 시간의 경과에 따라 비정상적으로 발생한다. 유한요소법으로 이것들의 거동을 해석한 후 다음과 같은 결론을 얻었다. 1) 용접 초기에는 용접열원 위치에서 54∼48MPa의 상당 열응력을 나타내고, 캡스턴 드럼의 내부로 진행될수록 42∼18Mpa 정도의 열응력 분포를 보이며, 열응력 구배는 1mm당 3.6MPa의 기울기를 형성하고 있었다. 용접열원에서 0.004∼0.015mm정도의 미세한 변형량이 계산되었고 좌측 자유단으로 진행하면서 0.03∼0.033mm의 변형량은 용접초기에 열충격 현상으로 발생한 것으로 사료되므로 이에 대한 대비책이 있어야 한다. 2) 용접 중반부에서는 상당 열응력 크기는 용접 초기보다 다소 작아져서 최대 51MPa, 최소 11.3MPa을 보여주며 열응력 기울기도 다소 완화된다. 이것은 용접 열원이 이동하면서 발생하는 예열효과로 상당 열응력이 감소한 것으로 사료된다. 상당 열변형의 크기는 최대 0.04mm, 최소 0.0045mm 정도를 형성하고 있고, 용접열원의 진행으로 전체적인 변형 양상이 용접진행 방향과 동일하게 이동하고 있다. 3) 용접공정의 후반부는 상당 열변형량이 최소 0.005mm, 최대 0.045mm 정도이므로, 정밀한 용접가공을 위해 반대방향에 지그나 고정구를 설치해야 한다. 상당 열응력의 구배는 모재 내부로 진행된 양상을 보이고 있으나 열응력의 절대 크기는 최소 3MPa에서 최대 27MPa로 작아졌다. 이 것은 용접의 이동열원이 제거됨으로서 모재 내부의 열응력이 현저히 저하되었음을 의미하지만, 잔류 열응력이 존재하므로 뜨임처리와 같은 후처리가 요망된다.

• Journal of Welding and Joining
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• 제20권6호
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• pp.72-72
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• 2002

Corrosion and tensile properties of zircaloy-4 cladding tube having a laser welding part in elevated temperature are studied to present the criterion of quality evaluation in nuclear reactor and find the scientific basis of SCC, with laser welding method using by coupling up cladding tube to end cap. In the result of tensile test(400℃), the fracture is not happened in the welding part but base metal and the result of corrosion test(400℃ 1500psi steam), corrosion rate of the molten zone and PMZ is a little higher than the other zone.

• Journal of Welding and Joining
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• 제13권3호
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• pp.77-88
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• 1995

A prediction method for determining the welding residual stress by artificial neural network is proposed. A three-dimensional transient thermomechanical analysis has been performed for the CO$_{2}$ arc welding using the finite element method. The first part of numerical analysis performs a three-dimensional transient heat transfer analysis, and the second part then uses the results of the first part and performs a three-dimensional transient thermo-elastic-plastic analysis to compute transient and residual stresses in the weld. Data from the finite element method are used to train a backpropagation neural network to predict the residual stress. Architecturally, the fully interconnected network consists of an input layer for the voltage and current, a hidden layer to accommodate the ailure mechanism mapping, and an output layer for the residual stress. The trained network is then applied to the prediction of residual stress in the four specimens. It is concluded that the accuracy of the neural network predicting method is fully comparable with the accuracy achieved by the traditional predicting method.