• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.210-217
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic restoration and pile-up was proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1-l0mm. The result of the investigation will be applied to the fabrication of the hyper-fine pattern and mold.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.164-168
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• 2007

Deformation of a shadow mask is one of the problems encountered during the deposition of organic materials for manufacturing large size OLED. The larger the glass substrate, the larger the shadow mask becomes. But as the size of the shadow mask increases, its deformation becomes more severe, thereby making it difficult to deposit organic materials in a precise pattern on a substrate. In this paper, a new type mask-frame structure is proposed. The proposed mask-frame structure making a curved mask has the ability of reducing drooping of mask. The test frame is fabricated and evaluation experiments are performed.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.47-54
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic re cover and pile-up were proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1 -l0nm. Comparison between the experimental data and numerical result demonstrated that the finite element approach is capable of reproducing the loading-unloading behavior of a nanoindentation test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1174-1177
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic recover and pile-up was proposed. The indenter was modeled a 3D rigid surface. Minimum mesh sizes of specimens are 1-10nm. Comparison between the experimental data and numerical result demonstrated that the finite element approach is capable of reproducing the loading-unloading behavior of a nanoindentation test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.

• Tribology and Lubricants
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• v.10 no.3
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• pp.62-70
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• 1994

An analytical model of the stress field caused by sliding indentation of brittle materials is developed. The complete stress field is treated as the superposition of applied normal and tangential forces with a sliding blister approximation of the localized inelastic deformation occuring just underneath the indenter. It is shown that lateral cracking is produced by the sliding blister stress field and that median cracking is caused by the applied contact forces. The model is combined with an experimental volume change measurements to show that the relative magnitude of tensile stresses governing lateral crack and median crack growth varies with the magnitude of the applied load. This prediction is consistent with the different regimes of experimentally observed cracking in soda-lime glass.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.333-336
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• 2002

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numberical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic restoration and bur was proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1-l0nm. The result of the investigation will be applied to the fabrication of the hyper-fine pattern and mold.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.293-296
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• 2005

The tensile properties of GFRP(glass fiber reinforced polymer) rods with various surface deformation produced by RTM(resin transfer molding) process were analyzes experimentally. Two types of GFRP rods with different surface deformation manufactured by RTM process in domestic area and two types of GFRP rods imported were considered in this study. All testing procedures including specimens preparation, set-up of test equipments and measuring devices were made according to the ASTM D3916-02 recommendations. From the test results, it was found that wave-type GFRP rod made by RTM process showed the highest tensile strength due to the highest fiber volume ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.297-300
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• 2005

The bond characteristics of GFRP(glass fiber reinforced polymer) rods with various surface deformation produced by RTM(resin transfer molding) process were analyzes experimentally. Two types of GFRP rods with different surface deformation manufactured by RTM process in domestic area and two types of GFRP rebars imported were considered in this study. All testing procedures including specimens preparation, set-up of test equipments and measuring devices were made according to the CSA S806-02 recommendations. From the test results, it was found that deformed-type GFRP rod manufactured by RTM process showed the highest bond strength among test specimen. But, wave-type GFRP rod made by RTM process show the lowest value due to the splitting failure of concrete caused by the wedge action of waved surfaces on GFRP rods.

• Journal of the Korean GEO-environmental Society
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• v.14 no.9
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• pp.39-47
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• 2013

Local deformations in back filling materials of two sands and one glass bead with different particle shapes behind a rigid retaining wall were studied. Two kinds of boundary conditions were compared: active wall translation and active rotation of the wall about its toe. Effect of the speed of active wall translation was also investigated. The digital image correlation method was used to analyze local deformation developments inside the materials. Test results showed that particle shape and density mainly influence the inclination angle and width of the shear band. The general shear band pattern is strongly dependent on the wall movement mode, while it was little influenced by particle shape. Within a limited range of wall speed in this study, shear band became wider and local deformation became larger with increase of wall speed.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.139-146
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• 2004

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation scratch test was studied with numerical method by ABAQUS S/W. Brittle materials (Si, Pyrex glass 7740) were used as specimens, and forming conditions to reduce the elastic recovery and pile-up were proposed. The indenter was modeled as a rigid surface. Minimum mesh sizes of specimens are 1-l0nm. Variables of the nanoindentation scratch test analysis are scratching speed, scratching load, tip radius and tip geometry. The nano-indentation scratch tests were performed by using the Berkovich pyramidal diamond indenter. Comparison between the experimental data and numerical result demonstrated that the FEM approach can be a good model of the nanoindentation scratch test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.