• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.651-657
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• 1996

Industrial products are getting more and more complex. The number of parts or components and the variety of manufacturing processes are increasing. This leads to rapid product oriented machine tools. The process integrated CNC lathe is one of the these machine tools which can produce numerous parts and various machining processes and reduce the lead time and non-machining time. Therefore this study deals with the design technique of a process-intergated CNC lathe which can reduce the tact time and production cost by the speed-up of the tooling system and the high-speed machining oriented construction of 2 spindles and 2 turrets.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.76-79
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• 1999

The study has been performed for the relation between die and product in forward extrusion by the experiment. Strains of the die have been given by the simple experiment using the strain gauge located at the outer surface of the die and the history of the deformation of the die and product is given by the experiment and Lame's formula. The inner pressure of the die causes the deformation of die that affects the accuracy of dimension and shape of product. The product with accurate dimension and shape can be obtained by analysing elastic deformation of the die during process. The deformation of the die during metal forming process has been usually predicted by the experience of industrial engineer or finite element analysis. But it is difficult to predict the dimension of product at unloading and ejected states. The study has given useful results for the deformation history of the die and product through the experiment and Lame's formula at forward extrusion for solid cylinder and can be applied to the die design for product with accurate dimension.

• 정보저장시스템학회논문집
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• 제8권1호
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• pp.33-38
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• 2012

To investigate of load/unload performance, FE (finite element) model of conventional suspension and HAMR suspension were made. The FE models were verified by modal analysis. In the loading simulation, the conventional system could stably load onto the disk without contact. On the other hand, the HAMR suspension which had an optical fiber and prism occurred slider - disk contact. In the unloading process, the conventional system was unloaded without contact. However, in the HAMR suspension, the contact between slider and disk was occurred at the moment that the dimple was separated during unload process. Therefore the load/unload performance of HAMR decrease with high stiffness, it is necessary that stiffness of HAMR suspension should reduced with design parameters of optical fiber and prism.

• 소성∙가공
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• 제10권1호
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• pp.75-79
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• 2001

The study has been performed for the relation between die and product during forward extrusion by the experiment. Stains of the die have been given by the simple experiment using the strain gauge located at the outer surface of the die. The history of the deformation of the die and the product has been given by the experiment and Lame's formula. The inner pressure of the die causes the deformation of die that affects the accuracy of dimension as well as shape of the product. The product with accurate dimension and shape can be obtained by analysing elastic deformation of the die during the process. The deformation of the die during metal forming process has been usually predicted by the experience of industrial engineer or finite element analysis. But it is difficult to predict the dimension of the product at unloading and ejected states. In the present study, useful results for the deformation history of the die and the product were obtained through the experiment and Lame's formula in forward extrusion which can be applied to the die design for the product with accurate dimension.

• Geomechanics and Engineering
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• 제27권6호
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• pp.583-594
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• 2021

The gas permeability behavior of unsaturated bentonite-based materials is of major importance for ensuring effective sealing of high-level radwaste repositories. This study investigated this by taking a sample of Granular Bentonite Material (GBM) at the end of the Engineered Barrier Emplacement (EB) experiment in the Opalinus Clay, placing it under different humidity conditions until it achieved equilibration, and testing the change in the gas permeability under loading and unloading. Environmental humidity is shown to have a significant effect on the water content, saturation, porosity and dry density of GBM and to affect its gas permeability. Higher sensitivity to confining pressure is exhibited by samples equilibrated at higher relative humidity (RH). It should be noted that for the sample at RH=98%, when the confining pressure is raised from 1 MPa to 6 MPa, gas permeability can be reduced from 10^-16 m² to 10^-19 m², which is close to the requirements of gas tightness. Due to higher water content and easier compressibility, samples equilibrated under higher RH show greater irreversibility during the loading and unloading process. The effective gas permeability of highly saturated samples can be increased by 2-3 orders of magnitude after 105℃ drying. In addition, cracks possibly occurred during the dehydration and drying process will become the main channel for gas migration, which will greatly affect the sealing performance of GBM.

• 한국가스학회지
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• 제26권5호
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• pp.49-57
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• 2022

미래에 수소 산업이 활성화되면 LH2 멤브레인 저장탱크 인수기지는 대용량 액화수소를 저장하고 송출할 수 있는 주요한 방안이다. 현재 이러한 인수기지가 존재하지 않기에, 기존 LNG 멤브레인 저장탱크 인수기지 설계 자료를 참고하여 기지 공정모사 모델을 완성하였다. 이 모델을 베이스로 하여 멤브레인 저장탱크 인수기지 운영에서 매우 주요한 인자인 기지 설계조건 변화에 따른 BOG 발생량을 예측하였다. 이를 통하여 LH2 멤브레인 저장탱크 인수기지가 운영될 때를 대비하여 하역시 BOG 발생량을 최소화 할 수 있는 적절한 운전조건을 검토하고자 하였다.

• 한국CDE학회논문집
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• 제20권3호
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• pp.291-297
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• 2015

A water jet cleaning robot system for micro drill bits is to refurbish micro drill bits used for the PCB manufacturing process. It can refurbish drill bits with the minimum diameter of ${\phi}0.15{\sim}0.075mm$ of which the total quantity have been discarded before. Micro drill bits with the minimum diameter of ${\phi}0.075mm$ can be cleaned by applying the water jet cleaning robot system out of the manual ultrasonic cleaning in the past for the cleaning equipment as the initial process in refurbishing. This study analyzed problems, while applying the apparatus mechanism for the workability such as the robot traces of Transfer Robot I and II, drill bit loading and unloading, and cleaning tasks in the water jet cleaning robot system in an effort to carry out simulations. In addition, the cleaning work process was optimized as the work process was verified in advance and the production quantity was analyzed through simulations.

• 한국기계가공학회지
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• 제14권5호
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• pp.15-21
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• 2015

The glass used for Mobile Camera Window is required to have high strength. Cell type manufacturing by means of CNC is widely used for camera window. Individual loading and unloading is needed for each process, such as painting and PVD, in cell type manufacturing. The purpose of this study is to search the enhanced manufacturing process with sheet type throughout bulk unit production in painting and PVD. This study includes sheet type manufacturing processes such as laser cutting, wet etching, 2nd tempering, printing, and AF/AR coating.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.116-119
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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. 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 1-10nm 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.

• 한국기계가공학회지
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• 제11권1호
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• pp.95-100
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• 2012

A deck crane is installed on the deck of a ship when there is no adequate facility for loading and unloading in dock or harbor. Deck cranes in Korea have been imported from abroad, and the import-substitution effect will arise if its production can be localized. Now, it is required to suggest the structural design of a deck crane that meet the domestic criterion, considering loading condition. In this study, the structural analysis of a pedestal in the deck crane was peformed by finite element method to investigate the strength requirement. In addition, the structural design of a pedestal was suggested by using ANSYS and VisualDOC. The optimized structure of a pedestal was determined, considering lightweight design.