• International Journal of Precision Engineering and Manufacturing
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• 제4권1호
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• pp.5-8
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• 2003

The rectangular deep drawing process is widely used in sheet metal forming, but there are various associated defects, such as earing, wrinkling, tearing, etc. In order to avoid such defects, an optimum blank shape is required. Such an optimum blank shape cannot be generalized because deep drawing processes are involved in complex process parameters. So, it is necessary to do systematic research to determine the optimum blank shape for the deep drawing process. In this study, a rectangular cup drawing test has been carried out to determine the optimum blank shape for various stainless steel sheets. From the test, a new blank model, which has no earing, is propsed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 압출 및 인발 심포지엄
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• pp.56-59
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• 1999

In the present study, in order to investigate the effect of the corner filling in the drawing of the rectangular rod from a round bar, the drawing of the square rod from a round bar has been simulated by using rigid-plastic finite element method and artificial neural network has been introduced to reduce the number of simulation. The experimental investigation has been also implemented to verify the efficiency of the application of results of present and previous study. According to the results of present and pervious study, the combination of semi-die angle gives a great effect on the corner filling in case of the irregular shaped drawing process, but, in case of the regular shaped drawing process, the main process variable on the corner filling is reduction in area.

• 소성∙가공
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• 제8권5호
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• pp.449-453
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• 1999

Sheet metal forming process is a non-linearity problem which is affected by various process variables, such as geometric shape of punch and die, frictional characteristic, etc.. Therefore, the knowledge of the influence of the process variables is needed in the design of sheet metal working processes. In this paper, cylindrical cup drawing tests for blank holding force, punch speed and lubrication between sheet material and tool were carried out to investigate the influence upon sheet formability. Experimental results were discussed about the defects on the deformation behaviors during the forming process.

• 소성∙가공
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• 제7권2호
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• pp.127-138
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• 1998

Process design of multi-step wire drawing process, conducted by means of finite element analysis and ANN(Artificial Neural Network) has been considered. The investigated problem involves the ade-quate selection of the drawing die angle and the correspondent reduction rate in the condition of desired initial and final diameter. Combinations of the process parameters which are used in finite ele-ment simulation are selected by using the orthogonal array. Also the orthogonal array. Also the orthogonal array and the results of finite element simulation which are related to the process energy are used as train data of ANN. In this study it is shown that the application of new technique using ANN and Othogonal array table to the process design of metal forming process is useful method.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.105-108
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• 2000

Finite element analysis of a multi-stage deep drawing process is carried out for the die design of rectangular cup drawing with the large aspect ratio. Simulation is performed for thorough investigation of unfavorable mechanisms in the initial design. The analysis reveals that the difference of the drawing ratio and the irregular contact condition produces non-uniform metal flow to cause wrinkling and severe extension. In this paper, the modification guideline is proposed in the design of the process and the tool shape. The analysis result confirms that the modified design not only improves the quality of a deep-drawn product but also reduces the possibility of failure.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.99-102
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• 1999

In this study, to investigate the effect of process variables such as reduction in area, semi-die angle and the rectangular ratio to the corner filling which influences the dimensional accuracy of the final product in the drawing of the cluadrangle rod from a round bar, it has been simulated by three dimensional rigid-plastic finite element method. In order to reduce the number of simulation artificial neural network has been introduced. Also, through the experimental investigation, the present results have been implemented on the industrial product. In results, the main process variable is the combination of the semi-die angle in case of the irregular shaped drawing process and reduction in area in the event of regular shaped drawing process, respectively.

• 한국정밀공학회지
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• 제16권10호
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• pp.101-108
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• 1999

Most of researches for deep drawing process have been performed on the formability of axisymmetric blank, but there is an insufficient study on the formability of non-axisymmetric blank. In addition, the conventional blank shape has been determined by the trial-and-error method using industrial experience and post processing test. Therefore only approximated shape of the blank can be presented. In this study, the optimal blank shape and concrete drafting method in deep drawing process with biaxisymmetric elliptical shape is proposed. Through the deep drawing experiment, it is found that the optimal blank shape gives the most uniform thickness of the products in the first process

• 소성∙가공
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• 제7권6호
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• pp.519-529
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• 1998

In automotive industries the stamping of laser-welded blank gives many merits which bring about dimensional accuracy, strong body assembly and high productivity. However the welding of blanks with different thickness or/and different strength materials introduces many challenging formability problems for process development and tool design. in this paper the deformation characteristics for deep drawing process of laser-welded blank with different thickness sheets are investigated by experiment as well as by FEM simulation. The blank holding force ratio to avoid the movement of weld line was suggested and compared with the experimental result for cylindrical and rectangular cup drawing process. The optimal location of weld line in laser-welded blank with different thickness sheets is calculated to compensate for the movement of weld line on deep drawing process. In addition the effect of location of weld line on formability is clarified using FEM simulation.

• Design & Manufacturing
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• 제13권1호
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• pp.31-35
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• 2019

For manufacturing upper housing product of mechanical control valve, the progressive drawing process was conducted experimental. Then, the center of the product was cut to measure the thickness of the product. As a result, the following conclusions were obtained. By means of a stand-alone pad provided with sufficient pressure, it is possible to prevent the occurrence of wrinkles in the die pad product of the drawing process. As a result of the experiment, it was considered that the flange bottom of the product and the lower edge of the product are made thick in thickness, the top edge and the top surface are thin. It is considered that this is due to the size and roughness of the entrance edge radius of the die in the drawing process, and the inflow of the material by the die pad.

• Design & Manufacturing
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• 제16권2호
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• pp.60-65
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• 2022

In the pultrusion process for the CFRP (Carbon fiber reinforced plastic) rectangular pipe, the drawing device is eseential which can continuously produces products and draws the carbon fiber tow. In addition, since the degree of cure changes depending on the temperature and the temperature ditribution of the curing mold changes depending on the pultrusion speed, the temperature distribution of the curing mold under certain conditions must be studied before processing. In this study, in the pultrusion process using a closed impregnation method, which has several advantages compared to the general pultrusion process using a open bath impregnation method, the drawing force required to pull the carbon fiber tows and the temperature distribution of the curing mold was analyzed to design the drawing device and the curing mold efficiently.