• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.27-30
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• 2004

Clad wire , which has the advantages of the high strength of a steel core and the electro-conductivity, corrosion resistance of a copper layer, is widely being used the telecommunications, electric-electronic and military technology industries, among others. It is important to obtain uniform coated rate when producing clad wires. Clad wire drawing process can be influenced on damage and coated rate of core and sleeve by process variables as semi-die angle and reduction in area. Therefore, in this study, the finite-element results established in previous study is used to analyze the effect of the various forming parameters, which included the semi-die angle, reduction in area etc. The coated rate will be predicted with observation copper coated rate variation according to total reduction in area and the optimal pass schedule will be set up through proper reduction in area and semi-die angle variation.

• Journal of Ocean Engineering and Technology
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• v.21 no.5
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• pp.33-38
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• 2007

The welding methods have been applied in the most structural products from multi-field of automobile, ship construction and construction, and so on. The structure steel must have enough strength of structure. In this study, SS400 steel and STS304 steel were used to estimate the corrosion characteristics of the weld thermal cycle simulated HAZ. To evaluate the corrosion characteristics, also, the materials with two conditions were used in 3.5% NaCl. The one is to the drawing with diameter of ${\Phi}10$ and the other is to the residual stress removal treatment. The electrochemical polarization test and immersion test were carried out. From test results, corrosion potential, corrosion current density, weight loss ratio and corrosion rate were measured. In the kinds of SS400 steels, corrosion potential of weld thermal cycle simulated specimens after the heat treatment showed somewhat the direction of noble potential. And in the base metal to be drawing weight loss ratio and corrosion rate occurred higher than the other kinds. In the kinds of STS304 steels, the result of base metal to be drawing was similar to results of SS400 steels, too. Two kinds of $750^{\circ}C$ and $1300^{\circ}C$ of weld thermal cycle simulation after the heat treatment were rather higher than the other kinds in weight loss ratio and corrosion rate.

• Transactions of Materials Processing
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• v.17 no.7
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• pp.517-522
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• 2008

A visco-plastic self-consistent (VPSC) polycrystal model has been applied to simulate texture simulation and anisotropic properties of DP steels during deep drawing process. In order to evaluate the strain path during deep drawing, a steady state was assumed in the flange part of deep drawn cup. The final stable orientations were strongly dependent on the initial location in the blank. The evolution of anisotropy of DP steel sheets has been demonstrated through comparison of plastic strain rate vector at the different plastic strain levels.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.396-399
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• 2008

A visco-plastic self-consistent (VPSC) polycrystal model has been applied to simulate texture simulation and anisotropic properties of DP steels during deep drawing process. In order to evaluate the strain path during deep drawing, a steady state was assumed in the flange part of deep drawn cup. The final stable orientations were strongly dependent on the initial location in the blank. The evolution of anisotropy of DP steel sheets has been demonstrated through comparison of plastic strain rate vector at the different plastic strain levels.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.531-534
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• 2008

A new forming process of the large-size forging within the limit of forming loads is developed by introducing the drawing process, which usually used to apply to sheet forming. For the development of the forming process, corresponding numerical simulation are carried out. The approach is based on the Taguchi method, and utilize the DOE for design of FEM analyses. In this study, the important factors are chosen at first, and then the concept of signal-to-nose(S/N) rate is applied to evaluate the formability of large size forging-products, and each value of the design parameter is determined.

• Journal of Korean Association for Spatial Structures
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• v.7 no.1 s.23
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• pp.71-78
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• 2007

Stainless steel is very famous for using of industrials structure and joint elements. Stainless steel wire drawing is one of the most ancient crafts. But there's not any standard size of tapered die during tile drawing. This paper was studied die angle and dimension of whole die by using AFDEX drawing simulator. Stress, metal flow and strain rate was analyzed by AFDEX tools during the wire drawing. So optimum data of during dies was taken from them. Simulation data was correspond with experimental data. The results of the optimum dies are shown that (1) Reduction angle is $13.8^{\circ}$ (2) Bark relief angle is $20^{\circ}$ (3) Bearing length is 0.7975mm (4) Bearing dia is 0.2393mm The research of the optimum result when the make dies is connected an enterprise. After researching, I hope that indirection effect creation make development situation of the manufactural technical, practical application of the other die size by the detail data, utility factor and economical efficiency.

• Journal of KIBIM
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• v.10 no.4
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• pp.22-31
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• 2020

Shop drawing tasks conducted after finishing coordinated or engineering design have great influences on the quality and cost of a project. However, despite the development of commercial BIM applications, shop drawings have mainly produced manually in certain engineering fields. Incorrect shop drawings with human errors have occurred various problems such as cost overrun, time delay and reworks. An automated shop drawing publishing from BIM is expected to resolve these problems. Despite attempts for automate shop drawing production, the field of mechanical, electrical and plumbing (MEP) is yet regarded challenging due to complexity of components and connection. In this research, we develop a process for automated producing 3D MEP shop drawings in BIM environment as following steps: to analyze conventional MEP shop drawing process, to identify detailed process that can be automated, to classify existing MEP objects and assign codes usable in BIM, and to develop an application. The validation of automated process is conducted against 10 clean room projects in which MEP is more complex and its cost is higher than other projects in terms of productivity and workers' satisfaction. Results show that the number of manpower for shop drawing is reduced by 30%, and the working time is shortened by 31%. Personal opinions of involved practitioners is interpreted as positive as the average rate of agrement on practicability, easy-to-use and necessary retouch tasks is around 66%.

• Environmental Engineering Research
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• v.20 no.1
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• pp.99-104
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• 2015

The purpose of this study is to evaluate the performance of forward osmosis (FO) system for harvesting microalgae cultivated in secondary sewage effluent. Microalgae species used in this study were chlorella sp. ADE4. The drawing agents used for forward osmosis system were seawater and concentrate of sea water reverse osmosis (SWRO) system. Chlorella sp. ADE4 cultured in secondary sewage effluent illustrated moderate efficiency in removal of total nitrogen (TN) (68%) and superior performance in total phosphorus (TP) removal (99%). Comparison of seawater and SWRO concentrate as drawing agent were made in FO membrane separation of the microalgae. The result from this study depicts that SWRO concentrate is strong drawing agent in FO membrane system providing an average dewatering rate of $4.8L/(m^2{\cdot}hr)$ compared to seawater with average dewatering of $2.9L/(m^2{\cdot}hr)$. Results obtained from this study indicated that FO system could be viable option for harvesting the microalgae for further biodiesel production. SWRO concentrate as a drawing agent could be very important finding in field of membrane technology for disposal of SWRO concentrate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.2
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• pp.84-90
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• 2003

Magnesium alloys have been paid attention In automotive and industries as lightweight materials, and with these materials it has been attempted at deep drawing process for assessment of formability of sheet metal. For warm deep drawing process with a local heating and cooling technique, both die and blank holder were heated at warm temperature while the punch was kept at room temperature by cooling water. Warm deep-drawing process with considering heat transfer was simulated by finite element method to investigate the improvement of deep-drawability and temperature distribution of Mg alloy sheet. The effect of sham rate sensitivity index on the deformation profile was considered in this work and the simulation results revealed that considering heat transfer is very effective for deep-drawability of Mg alloy. The deformed blank In considering heat transfer was drawn successfully without any localized thinning and the cup height is higher in contrast to results of simulations in considering no heat transfer.

• Transactions of Materials Processing
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• v.21 no.4
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• pp.258-264
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• 2012

The forming failure of AZ31 alloy sheet during deep drawing processes was predicted by the FEM and ductile fracture criteria. Uniaxial tensile tests of round-notched specimens and FE simulations were performed to calculate the critical damage values for three ductile fracture criteria. The critical damage values for each criterion were expressed as a function of strain rate at various temperatures. In order to determine the best criterion for failure prediction, Erichsen cupping test under isothermal conditions at $250^{\circ}C$ were conducted. Based on the plastic deformation histories obtained from the FE analysis of the Erichsen cupping tests and the critical damage value curves, the initiation time and location of fracture were predicted under bi-axial tension deformation. The results indicate that the Cockcroft-Latham criterion had good agreement with the experimental data. In addition, the FE analysis combined with the criterion was applied to another deep drawing process using an irregular shaped blank and these additional results were verified with experimental tests.