• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.4
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• pp.440-451
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• 1985

This study is concerned with the analysis of cutting force system acting on ball-nose end mill in three-dimensional surface machining process. Conical tipped circular cutting edge element model and free surface machining process types are proposed to apply oblique cutting theory, and then derived equations are used for numerical approach of cutting force curves by matrix method. This approach has a good agreement with experimental results both in magnitude and shape within the range of 15 percent, which was conformed on 6061-T6 aluminum workpiece having twofold curvatured surface. From the cutting load variation to edge location, it is confirmed that circular cutting edge shapes has a better cutting ability than that of straight and both have a singularity near a tool point. It is also verified that what kind of machining condition is recommendable for three-dimensional machining process in connection with deflection of the cutter to workpiece and tool point wearing or system stability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.228-233
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• 2007

An experimental and numerical approach has been carried out to characterize the noise and the safety of circular diamond saw with chinks by laser-cutting. The sound pressure level of a circular diamond saw with chinks was measured when cutting workpieces. Therefore, frequency analysis results show us that the sound level was reduced as position of chinks approach to out-diameter. But the safety of circular diamond saw was lower due to the stress concentrated at the edge of chinks while cutting workpieces. FEM analysis was used for safety evaluation with the variation position of chinks. The noise characteristics of circular diamond saw were also estimated during cutting test.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.15-21
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• 2000

This study presents a procedure for analyzing chip-tool friction and shear processes in 3-D cutting with a single point tool. The edge of a single point tool including a circular nose is modified to an equivalent straight edge, thereby reducing the 3-D cutting with a single point tool to the equivalent of oblique cutting. Then, by transforming the conventional coordinate systems and using the measurements of three cutting force components, the force components on the rake face and shear plane of the equivalent oblique cutting system can be obtained. As a result, the chip-tool friction and shear characteristics of 3-D cutting with a single point tool can be assessed.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.190-196
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• 1999

In this study, a procedure for analyzing chip-tool friction and shear processes in 3-D cutting with a single point tool has been established. The edge of a single point tool including circular nose is modified to the equivalent straight edge, then 3-D cutting with a single point tool is reduced to equivalent oblique cutting. Transforming the conventional coordinate systems and using the measured three component of cutting forces, force components on the rake face and the shear plane of the equivalent oblique cutting system can be obtained. And it can be possible to assess the chip-tool friction and shear characteristics in 3-D cutting with a single point tool.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.228-236
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• 2002

In this study, the carbon steels, SM20C were machined with the tungsten carbide tipped circular saw to clarify the cutting-off characteristics in terms of tool wear. The results show that an improved performance in view of both the tool wear and the cutting efficiency was obtained by using oil base cutting fluid at the cutting speed of 100m/min with the feed of 0.06mm/tooth. The rake angle of 10$^{\circ}$ , clearance angle of 8$^{\circ}$ , nose radius of R0.1mm, and end cutting edge champer of 0.1mm$\times$25$^{\circ}$ are believed as the best tool geometries. The tool wear decreases due to using the saw of the disk of STS5 and the tool material of P30.

• The Journal of Korean Academy of Prosthodontics
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• v.16 no.1
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• pp.32-37
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• 1978

The purpose of this study was to apply the position, the form and the angle of the attrition in the natural maxillary central incisors shown on the labial surface to the artificial teeth in the field of prosthetic dentistry. So we should exactly alter the molds of artificial teeth in individual cases in order to make artificial teeth more natural. 226 extracted teeth of the maxillary central incisors were chosen as materials. I have exactly examined the teeth with a magnifying glass and a circular graduator under concentrated light. The observation brought me the following results: 1) The attrition was most prevailing at the range from the mesial angle to the middle part of cutting edge in the left maxillary central incisor, and distal angle of cutting edge in the right maxillary central incisor. 2) On the attrite form of both angles, the angulated form was more than 4 times as frequent as rounded form in the mesial angle, and almost equal in the distal angle. 3) On the attrite form of cutting edge, mesial attrite form including mesial angle was most frequent in the left maxillary central incisor, and distal attrite form including distal angle in the right maxillary central incisor. 4) The angle made by the labial surface and the attrite surface was about $39^{\circ}$, and more than 70% of the total examined teeth were included at the range from $31^{\circ}\;to\;50^{\circ}$. 5) None attrite form at the cutting edge was about 12% and completely attrite form at the cutting edge was about 27% of examined teeth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.48-56
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• 2021

Tungsten carbide (WC) circular saws have been widely used to cut plywood. Recently, expensive polycrystalline diamond (PCD) were adopted to extend the tool life of circular saws. This study developed a PCD-WC combination circular saw and compared its performance with that of existing WC and PCD saws. Flank wear of WC saw blades and edge chipping of rectangular PCD was observed during the experiments. The PCD-WC saw replaced half of the chamfered teeth with PCD and applied tough WC for all rectangular teeth. In the experiments, edge chipping was not observed in rectangular WC teeth and the flank wear of chamfered teeth was decreased compared with that of conventional circular saws.

• Journal of KSNVE
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• v.8 no.2
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• pp.324-330
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• 1998

The forced vibration analysis of the outer-clamped spinnig annular disk with arbitrary in-plane is formulated to investigate the influence of non-uniform tension on the cutting accuracy of wafer cutting machine. The arbitrary in-plan force along the outer edge of an annular plate is expressed as a Fourier series. Galerkin method and modal superposition method are employed to obtain the forced responses under the static force and the impulse force in astationary coordinate. Through qualitative and quantitative analyses, it can be found that forced and impulse responses are sensitive to the non-uniformity of in-plane force, which can bring a bad effect to the accuracy of wafer cutting process. Also, in case of a spinning disk with non-uniform in-plane force, critical speed is required to define in a different way, compared with conventional definition in axi-symmetrical spinning disk.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.68-77
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• 2015

This study was the use of the finite element method in the deep drawing process of a rectangular shell cup. The aim was to analyse the equivalent strain in the workpiece and to find out what happened to the disc blank sheet before the forming by stamping. The rectangular shell cup was $24{\times}30{\times}20$ mm. and made of 2mm.thick SUS 403 and SUS 304 stainless steel. There were 3 types of blank sheets: 1) square sheet 2) 45 degree angled edge cutting sheet 3) circular sheet. It was found out that the drawing up with the use of 3 types of blank sheet made of SUS 304 stainless steel had no risk in the workpiece. For the stamping of the rectangular shell that used a square sheet made of SUS 403 stainless steel, it was found out that there was no risk in the work piece, but with the use of 45 degree angled edge cutting sheet or round sheet, the work piece had a risk to be damaged.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.292-299
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• 2012

This paper proposes the design of circularly polarized multi band antenna for a non-linear junction detector (NLJD) system. In order to design for broad bandwidth, the CPW (Co-Planar Waveguide) feeding method is considered in this design. In order to realize the circular polarization, the axial ratio was controlled by inserting a $45^{\circ}$ inclined slot on radiating element and by cutting an edge of the radiating patch. Measurement results of return loss, bandwidth, axial ratio, polarization pattern and gain are agreed well with their simulation results in interested frequency band at 2.4~ 2.44 GHz, 4.84~4.92 GHz, and 7.28~7.32 GHz.