• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1016-1019
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• 2005

In the cutting of plate steel, the quality of the cut surfaces is strongly dependent on the cutting condition such as cutting speed, plate thickness, power, kerf width and gas pressure etc. The cutting tests of Steel Automobile Press Hot were carried out using $CO_2$ Laser cutting machine. The kerf width and surface roughness of a section are examined at various cutting conditions. This paper deals with cutting characteristics of Steel Automobile Press Hot(SAPH400) using $CO_2$ Laser Cutting Machine.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.245-248
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• 2004

The press cutter is productive equipment that practically manufactures materials such as fabrics, papers, films, leathers, rubbers etc. into the desired shapes using cutting method. Plate cutting process is one of the primary energy absorbing mechanisms in a grounding or collision event. The cutting mechanism is complicated and involves plastic flow of plate in the vicinity of the tip, friction between wedge and plate, deformation of plate. In this paper, we studied the effect of friction between cutter and plastic sheet for producing precise and superior products. The press cutter is analyzed numerically using MARC finite element program according to the variation of friction coefficients. The FEM results showed that normal stress, equivalent cauchy stress, normal total strain, equivalent total strain are good when friction coefficient is 0.0 and shear stress, shear total strain are good when friction coefficient is 0.8.

• 한국정밀공학회지
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• 제21권5호
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• pp.46-54
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• 2004

A cutting force model predicting the dynamic force induced by the axial vibration of it plate in face milling is introduced. When a plate face is milled, deformation in tool axial direction is considerable. Therefore, cutting forces are affected by not only inner-outer modulation in feed direction but also by axial deformation. A PTP (peak-to-peak) diagram made by the simulated dynamic force model is evaluated. The stability of the face milling process such as the chatter outset, and the stable cutting region can be simply estimated. Simulation results are compared with that of experiment.

• Journal of Biosystems Engineering
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• 제20권1호
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• pp.13-21
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• 1995

This study was conducted to investigate the cutting mechanism of reciprocating knife of combine harvester. The cutting operation of reciprocating knife with the arrangement of the low-cutting and the double-cutting was demonstrated through cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of reciprocating knives were analyzed using the developed program. The results are summarized as follows (1) The low-cutting type reciprocating knife was represented similar cutting characteristics to the standard type, but the maximum stalk-deflection was decreased as 1/2 level of the standard type. And the first ledger plate should be designed shorter than the second ledger plate. (2) The bunching area and the maximum stalk-deflection for the double cutting knife almost were not changed since cutting velocity ratio of 0.6, but the secondary cut were occurred at ratio of 0.8 and increased rapidly over these ratio. (3) The double cutting knife was recommended for the high speed combine, because its bunching area and the maximum stalk-deflection were decreased as 1/2 level of the standard type. (4) In order to maintain the proper cutting mechanism characterized by the bunching area, the maximum stalk-deflection and the secondary cutting length etc., the adequate cutting velocity at forward speed of 0.5㎧ to 1.2㎧ was from 0.3㎧ to 0.96㎧ for the double cutting knives.

• 화약ㆍ발파
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• 제38권2호
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• pp.13-21
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• 2020

철골 구조물의 발파해체에 사용하는 성형폭약은 국내외 사용이 제한적이거나 수급이 불가능한 경우가 많이 발생하며, 기존의 선형 성형폭약은 규모가 크고, 강재의 두께가 두꺼운 철골 구조물을 절단하기 위한 충분한 절단 성능을 확보하지 못하였다. 이러한 문제를 해결하기 위해 고폭속, 고압력의 산업용 폭약을 사용하여 금속제트를 발생시켜 절단 할 수 있는 장치가 필요하다. 본 연구에서는 철골 구조물의 발파해체에 적용하기 위해 3가지 타입의 장약용기를 제작하였다. 절단 성능 실험을 통해 다양한 두께의 H형 강재와 강판에 대한 절단 성능을 평가하였고, 실험결과 충분한 절단성능을 확인하였다.

• Journal of Welding and Joining
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• 제9권4호
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• pp.69-74
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• 1991

The Plasma Arc Cutting Method using high density and hight temperature beam is well applicable to the cutting of the nonferrous metal (Al alloy ) and stainless steel which are unable to be cut by the use of the oxy-fuel gas. This study focalizes on the cutting phenomena of the plate of (mm) thickness, since the cutting phenomena of thick plates have been rather thoroughly studied. In this study the cutting groove, adhesive phenomena of dross, surface roughness were measured according to the variation of cutting speed and compared with the case of mild steel plates. The result showed that the kerf width variation of Al alloy was similar to the case of mild steel, while that of the stainless steel differed from the mild steel. In the adhesive phenomena of dross, 6(mm) thick plates of Al alloy showed a difference from those of thick plates, but the stainless steel was similar to thick plates. The surface roughness variation of Al alloy wias minimum at 67 cm/min, while that of stainless steel was at 30cm/min.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.126-132
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• 2008

Cutting procedures whose qualifies are determined by various variables largely influences shipbuilding productivity. Particularly, defects in cutting shapes and cutting surface results in delay of the post shipbuilding stages such as welding and assemblage process. Because cutting procedures are influenced by various numbers of requirements according to the plate thickness, cutting precision can be maintained when the cutting conditions are appropriate. Existing cutting procedures utilize fossil fuels such as propane or ethylene as the main fuel component. Especially, when fossil fuel is applied to thick plate cutting, this process gives relatively slow cutting speed and generates large quantities of harmful polluting fumes. Recently, hydrogen-oxygen mixed gas generated by electrically dissociating water into Hydrogen and oxygen components is welcomed as an alternative fuel source. Also recent results report that alternative cutting fuel improves the cutting Dualities and speed. This paper presents that cutting characteristics and optimum cutting condition of hydrogen-oxygen mixed gas.

• 방사성폐기물학회지
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• 제19권3호
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• pp.279-287
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• 2021

For application in nuclear decommissioning, underwater laser cutting studies were conducted on thick stainless-steel plates for various cutting directions using a 6 kW fiber laser. For cutting along the horizontal direction with horizontal laser irradiation, the maximum cutting speed was 110 mm·min^-1 for a 48 mm thick stainless-steel plate. For cutting along the vertical direction with horizontal laser irradiation, a maximum speed of 120 mm·min^-1 was obtained for the same thickness, which confirmed that the cutting performance was similar but slightly better. Moreover, when cutting with vertically downward laser irradiation, the maximum cutting speed was 120 mm·min^-1 for a plate of the same thickness. Thus, the cutting performance for vertical irradiation was nearly identical to that for horizontal irradiation. In conclusion, it was possible to cut thick stainless-steel plates regardless of the laser irradiation and cutting directions, although the assist gas rose up due to buoyancy. These observations are expected to benefit laser cutting procedures during the actual dismantling of nuclear facilities.

• 화약ㆍ발파
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• 제36권2호
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• pp.10-18
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• 2018

철골 구조물의 발파해체에 사용하는 성형폭약은 국내외 대부분의 경우에 사용이 제한적이거나 수급이 불가능하여 적용하지 못하는 경우가 많이 발생한다. 이러한 문제를 해결하기 위해서는 산업용 폭약을 사용하여 금속 제트가 발생할 수 있는 장치가 필요하다. 본 연구에서는 금속 제트가 발생하는 강재 절단용 장약용기를 제작하였다. 절단 성능 실험을 통해 두께 25mm의 강판에 대한 장약용기의 절단 성능을 평가하였다. 또한 침투 과정 수치 모사와 절단 성능 실험에서의 결과를 비교하고, 두께 35mm와 70mm의 강판에 대한 절단 성능을 평가하였다.

• 한국추진공학회지
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• 제22권6호
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• pp.134-141
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• 2018

본 연구에서는 MDF(Mild-detonating Fuse)를 이용한 선형분리장치 개발 가능성을 확인하기 위해 기초 연구를 수행하였다. 지름이 작은 금속(납) 튜브 내부에 화약(RDX)이 충전되어 있는 MDF를 활용한 알루미늄 평판 절개 기초 시험을 수행하였다. 평판의 두께와 MDF의 단위 길이당 화약량을 조절해가며 시험을 수행하였으며, 평판 두께와 화약량에 따른 절개 여부를 확인하였다. 시험 결과를 바탕으로 AUTODYN 기반의 수치 해석 모델을 개발하였으며, 정확한 파괴 조건을 결정하였다. 시험 및 해석 결과 분석을 통해 MDF의 알루미늄 평판 절개 메커니즘과 특성을 확인하였으며, 체계 적용 가능성을 확인하였다. 개발된 해석 기법을 활용하면 다양한 MDF 및 구조물에 대한 절개 가능 여부를 미리 확인하여 개발 과정에서의 시험 비용을 최소화 할 수 있다.