• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1995년도 특별강연 및 추계학술발표 개요집
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• pp.61-67
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• 1995

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 추계학술발표 개요집
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• pp.176-178
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• 1997

• 한국산업융합학회 논문집
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• 제6권1호
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• pp.43-48
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• 2003

점용접은 자동차를 제작하는데 사용하는 가장 유용한 용접법이다. 그러나 산업현장에서 직면하고 있는 가장 큰 문제점 중의 하나는 점용접의 용접성에 관한 문제이다. 본 연구에서는 강판의 두께가 1.6mm인 경우와 1.2mm인 경우에 대해 2점 점용접을 실시하여 인장강도를 증가시키고 용접의 흔적을 남기지 않게 하기 위한 조건을 찾는 것을 목적으로 하였다. 용접성에 영향을 미치는 많은 요소들이 있다. 그중에서 용접전극의 형상이 인장강도를 증가시키는 요소로 집중을 하면서 연구를 수행하여 다음과 같은 결과를 얻었다. 인장강도는 용접전극의 형상 및 팁직경 거리와 전류가 클수록 증가하였다. 시행 착오법을 통해 최적용접조건을 찾았고 그에 따른 최적전류인 9,000A와 전극의 형상 RF형을 찾았다. 경도시험결과는 인장력이 시험편에 작용할 때 열 영향부인 HAZ부에서 왜 파괴가 일어나는지를 설명해 주었다.

• 대한기계학회논문집
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• 제13권6호
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• pp.1156-1169
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• 1989

본 연구에서는 용접도중 발생할 수 있는 용접질 저항요인을 전극분리현상을 측정하여 파악하고 용접 열입력에 해당하는 용접전류를 학습제어방식(self-learning control)에 의하여 컴퓨터와 주변기기(interface)를 통해 조절함으로서 요구되는 균일한 용접질이 항상 보장되도록 하였다. 여기서 학습제어방식을 태택한 이유는 제어하고자 하는 대상의 동적 모델(dynamic model)이 없어도 제어기 이득의 선정이 비교적 자유롭고 용접 제어장치가 자체적으로 감지(monitoring)한 신호로 판단하여 제어동작을 취함으로서 용접시 축적되는 정보(data)가 용접기에 일종의 지능을 부여할 수 있어서 진보된 개념의 용접제어장치 개발의 가능성을 검토해 보기 위함이다.

• Journal of Welding and Joining
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• 제15권4호
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• pp.42-62
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• 1997

Resistance spot welding has been widely used in the sheet metal joining processes because of its high productivity and convenience. Recently, automobile industries are trying to replace partly steel sheets with aluminum alloy sheets. Among currently produced aluminum alloys, Al alloy sheets of Al-Mg-Si(6000 series) are being tested. Especially, 6000 series are the most probable substitute in view of strength and weldability. In this paper, an attempt was made to apply resistance spot welding to joining of dissimilar sheet metals (KS6383+SCPZn or KS6383+SHCP). An effort was made to balance heating rate in the Al alloy with that in the steel sheets by increasing electrode tip diameter. Although resistance spot welding of Al alloy sheet and sheet metals does not produce desirable nugget, it proved to have reasonable strength if optimal weld condition is found by tensile-shear strength and fatigue life test. Since spot weld joints in automobile are always experiencing repeated load, spot welding methodology proposed in this paper is found to be not suitable to automobile body manufacturing.

• 한국공작기계학회논문집
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• 제15권4호
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• pp.98-104
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• 2006

In this paper, for the purpose of investigation the acoustic emission(AE) behaviors during resistance spot welding process and tension test of spec steels. As the results present the resistance spot welding method that can get suitable welding qualities or structural integrity estimating method. The resistance spot welding process consists of several stages: set-down of the electrodes; squeeze; current flow; forging; hold time; and lift-off. Various types of AE signals are produced during each of these stages. For tensile-shear test and cross tensile test in resistance spot welded specimens, fracture pa 야 ems are produced: tear fracture; shear fracture; and plug fracture. Tensile-shear specimens strength appeared higher than cross tensile specimens one. In case of tensile-shear specimen happened tear fracture that crack happens in most lower plate. Also, in case of cross tensile specimens, upper plate and lower plate are detached perfect fracture was exposed increases a little as acting force is lower than ordinary welding condition. Therefore, the structure which is combined by resistance spot welding confirmed that welding design must attain so that shear stress may can interact mainly.

• 대한기계학회논문집
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• 제8권3호
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• pp.224-231
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• 1984

본 연구에서는 이상과 같은 점을 고려하고, 인장시험을 통해 최대용접강도를 나타내는 최적용접조건을 구한 다음, 최적조건하에서 박강판을 1점 점용접한 재료의 너깃주위에 관찰되는 파괴거동을 광탄성 응력분포거동과 관련시켜 고찰하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1993년도 특별강연 및 춘계학술발표 개요집
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• pp.115-119
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• 1993

Many qualitive analyses of sampled process variables have been attempted to predict nugget size in resistance spot welding process. In this paper, dynamic resistance and electrode movement signal which is a good indicative of the nugget size was examined by introducing an artificial neural network estimator. An artificial neural feedforward network with back-propagation of error was applied for the estimation of the nugget size. To assess the advantage of this method. results have been compared with conventional regression method.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.99-101
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• 2003

This study deals with the resistance spot welding of aluminized steels. According to the test results it was clear that the weldability of aluminized steels was equivalent to or better than that of Zn coated steel. Microstructural inspection revealed that molten aluminum that was repelled from the weld during the process, piled up at the split zone. The test results also demonstrated that the weld metal of aluminized steels could hardly produce the weld crack even higher welding heat Input was applied.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.149-151
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• 2003

The development of lightweight car bodies is the most prominent issue in the automotive industry today, in preparation of environmental regulations such as reduction of CO$_2$ emissions. Also, with the recent implementation of mandatory off-set collision test, many studies have been carried out to enhance the safety of automobiles. Recently, TRIP(Transformation Induced Plasticity) steel has developed as a prominent alternative due to its high strength and superior elongation. In this study, TRIP steel weldability is evaluated with lobe curve, continuous spot welds, shunt effect, and weld of edge position.