• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.500-503
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• 2003

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.223-228
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• 2003

In end milling processes, characterized by use of rotating tools, the underformed chip thickness varies periodically with the phase change of tool. In current study, as a new approach to analyse shear behaviors In the shear plane and chip-tool friction behavior chip-tool contact region during an end milling process. In this approach, an up-end milling process is transformed into an equivalent oblique cutting process. Experimental investigations for two sets of cutting tests i.e.. up-end milling and the equivalent oblique cutting test were performed to verify the presented model.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.422-427
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• 2004

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and to develop a software for design of end mill geometry.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1074-1079
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• 2003

In this paper, we conducted finite element analysis to investigate the residual stress redistributions of weldment due to cutting. To evaluate the effect of the residual stress on the fatigue behavior of weldment, test specimens are commonly cut from the weldment, but the distributions of the residual stress in the cut specimen should be different from those in the original weldment. Our work is to evaluate the difference between the residual stresses before and after weldment-cutting to understand the effect of cutting on the residual stress. Transient heat analysis, elastic-plastic mechanical analysis and element removal technique are used to simulate the welding and cutting procedures on the commercial finite element code ABAQUS.

• Tunnel and Underground Space
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• v.21 no.3
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• pp.151-163
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• 2011

The LCM test is one of the most powerful and reliable methods for designing the disc cutter and for predicting the TBM (Tunnel Boring Machine) performance. It has an advantage to predict the actual load on disc cutter from the laboratory test on the real-size large rock samples, however, it also has a disadvantage to transport and/or prepare the large rock samples and to need an extra cost for experiment. Moreover it is not easy to execute the test for jointed rock mass, and sometimes the design model estimated from the test can not be applied to the real design of disc cutter. In order to break this critical point, lots of numerical studies have been performed. PFC2D can simulate crack propagation and rock fragmentation effectively, because it is useful in particle flow analysis. Consequently, in this study, the PFC2D has been adopted for numerical analysis on cutting power of disc cutter according to the different angle of joint, the different direction of joint, and the different space of joint with jointed rock mass models. From the numerical analyses, it was concluded that the bigger cutting power of disc cutter was needed for reverse cutting direction to joint rather than for forward direction, and the cutting power of disc cutter was increased with decreasing the dip angle of joint and decreasing the space of joints in reverse cutting direction. The more precise numerical model for disc cutter can be developed from comparison between the numerical results and LCM test results, and the resonable guideline is expected for prediction of TBM performance and disc cutter.

• Design & Manufacturing
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• v.10 no.3
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• pp.1-7
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• 2016

In the semiconductor industry the memory and chip were developed to high density memory and high performance chip, so circuit design was also high integrated and the test bed was needed to be thin and fine pitch socket. LGA(Land Grid Array) IC socket with thin wall thickness was designed to satisfy this requirement. The LGA IC socket plastic part was manufacture by injection molding process, it was needed accuracy, stiffness and suit resin with high flowability. After injection molding process the side gates were needed to remove for further assembly process. ln this study, the cold press cutting process was applied to remove the gates. For design of punch and die, the cold press cutting analysis was implemented by$DEFORM-2D^{TM}$ ln consideration of the simulation results, an adequate punch and die was designed and made for the cutting unit. In order to verify the performance of cutting process, the roughness of cutting section of the part was measured and was satisfied in requirement.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.386-396
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• 2022

To analyze the influence of variables of roadheaders, the linear cutting testing data of pick cutter were collected from the former literatures. The input factors were set up as uniaxial compressive strength, cutting depth, cutting spacing, attack angle, skew angle, and output factors were determined as specific energy, average cutting force, maximum cutting force, average vertical force, and maximum vertical force. After composing a table of the design of experiment (DOE). The contribution level of each factor was calculated by analysis of variance (ANOVA). As a result, the factors having greatest influence on cutting force and specific energy were uniaxial compressive strength and cutting spacing.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1999.06a
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• pp.201-206
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• 1999

The influence of surface preparation methods after plasma cutting on the quality of welding zone is investigated. For comparison. three types of welded specimens are prepared by machining(YM), plasma cutting with light regrinding(WPG) and without regrinding(WP), by using three kinds of materials, carbon steel(S45C), stainless steel(Type304) and aluminum alloy (6061-T6). Nondestructive examination, hardness test, microstructure examination, and fracture toughness test are performed. The results show that there is no appreciable reduction in hardness or fracture toughness in WP specimens. But a little difference in heat affected gone size is observed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1008-1011
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• 2001

The purpose of this paper is to evaluate the chip breakability during turning using the experimental equation, which is developed by an orthogonal array method. The chip breaking index(CB), non-dimensional parameter is used in the evaluation of chip breakability. The analysis of variance(ANOVA)-test has been used to check the significance of cutting parameters. And using the result of ANOVA-test, the experimental equation of chip breakability, which consists of significant cutting parameters, has been developed.