• Title/Summary/Keyword: blank

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Evaluation of Blank Heating Processes by Thermal Stress Analysis (열응력 해석에 의한 블랭크 단조품 가열공정 평가)

  • Park, Sang-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4375-4380
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    • 2015
  • This study was performed to evaluate a newly proposed heating process of blank, which was used for Crank throw in the diesel engine, and provide design guidelines of heating processes. Non-linear numerical analyses were done using ANSYS program to investigate temperature and thermal stress distributions of blank during heating processes. The heating process consists of two stages; one is a heating stage with 20 hours, and the other is a holding stage with 12 hours, totaling 32-hour heating time. Based on analysis results, it was found that the temperature difference between the center and the surface of blank increased linearly during the heating stage but decreased gradually during the holding stage of heating processes, while max. equivalent stress, $12.5kg/mm^2$, was found at the center of blank after 10-hour heating time. As the guideline of blank heating process, it was recommended to keep the temperature difference between the center and the surface of blank to be within $150^{\circ}C$ when the environment temperature in furnace reaches $650^{\circ}C$ during a heating stage.

Effect of the bee venom aqua-acupuncture on the neuronal activities of catecholaminergic system in brainstem (봉독약침자극이 Catecholamine성 신경세포의 활성변화에 미치는 영향)

  • Kim, Hye-Nam;Nam, Sang-Soo;Lee, Yun-Hoo;Choi, Yong-Tae
    • Journal of Pharmacopuncture
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    • v.3 no.1
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    • pp.65-87
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    • 2000
  • This study was designed to evaluate the effect of the bee venom(BV) aqua-acupuncture on the neuronal activities of catecholaminergic(tyrosine hydroxylase : TH, dopamine ${\beta}$ hydroxylase : D${\beta}$H) system in the brainstem. After the BV aqua-acupuncture was applied on Chok-Samni(ST36) and the gluteal part(Blank locus) in rats. Also, the number of colocalization between catecholamine containing neurons and Fos immunoreactive neurons were analyzed by using the double immunohistochemical technique. The results of the experiments were summarized as follows : 1. In DR and LC, Chok-Samni group and the Blank locus group showed more significant increase in the number of colocalization between TH containing neurons and Fos immunoreactive neurons than the control group. Furthermore, Chok-Samni group showed more significant increase than the Blank locus group. Also, in Arc, Chok-Samni group showed more significant increase than the Blank locus group and the control group. 2. In LC, Chok-Samni group showed more significant increase in the number of colocalization between D${\beta}$H containing neurons and Fos immunoreactive neurons than the Blank locus group and the control group. Also, in A5, Chok-Samni group and the Blank locus group showed more significant increase than the control group. Chok-Samni group showed more significant increase than the Blank locus group. However, there was no significant change in A7. Consequently, the BV aqua-acupuncture increased more potent the number of Fos immunoreactive neurons and the activity of catecholaminergic neurons. Furthermore, the BV aqua-acupuncture was more effective on Chok-Samni than Blank locus group. These results indicate that the BV aqua-acupuncture is very effective therapy to control pain. The therapeutic effect of BV aqua-acupunture may associated with the endogenous modulatory system such as catecholamine. Those data from the study can be applied to establish the effective treatment of the BV for pain control in the clinical field.

Characteristics of the Subway Sign Blank through Cluster Analysis (군집분석을 통한 지하철 표지 여백에 대한 특성)

  • Hong, Sujeong;Oh, Heungun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.4
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    • pp.513-521
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    • 2019
  • The purpose of this research is to find out the preference of users on the characteristics of the subway sign blank. In detail, The purpose is to introduce the concept of designing various characteristics of the subway sign blank according to characteristics such as gender and age, etc. The methodology of this study is to investigate the preference of the characteristics of the characteristics of the subway sign blank space and analyze the preference of the whole group and the cluster group. A survey was conducted to investigate preferences. A cluster analysis was conducted to analyze the preferences. And a demographic and conjoint analysis was conducted for whole group and the cluster group. The attributes of the subway sign blank space for preference survey are as follow : top and bottom blank, side blank, border line blank, arrow thickness, 'station name' and 'line number' order. The results of the preference analysis are as follows. The importance of the attributes in the whole group is shown in the order of the border line blank, 'station name' and 'line number' blank, side blank, top and bottom blank, and arrow thickness. The cluster group is composed of 3 groups, 1 cluster is a woman who uses the subway almost every day, three to four times a week, and seems to prefer half the side blank. 2 crowd is the user who thinks that 60 or more subway signs are uncomfortable, and preferring the order of 'station name' + 'line number' order without border. The 3 clusters were men in their 20s and 30s, with a preference for 1/5 border line blank and thin arrow thickness. The conclusion is as follows. First, the characteristics of the subway sign blank must be designed consistently. However, it is necessary to consider various factors according to gender, age, and frequency of subway use for specific regions or routes. Secondly, It has been shown that, depending on the specific area or route, it is possible to design two or more types of design, not one type of standardized marking of the characteristics of the subway sign blank.

The Determination of Initial Blank Shape by Using the One-Step FEM (One-Step FEM을 이용한 초기 블랭크 형상 결정에 관한 연구)

  • Jung, Dong-Won;Lee, Sang-Je
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3 s.33
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    • pp.21-28
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    • 1999
  • In this paper, a finite element method for the determination of initial blank shape in sheet metal forming process will be introduced. The initial blank shape is determined by the only one step from the final to the initial blank. The used finite element inverse method adopted Henky's deformation theory, Hill's anisotropic yield criterion and simplified boundary conditions. Based on this theory. a three-dimensional membrane finite element code was developed. The developed code will be applied to several sheet metal forming examples for the demonstration of its validity.

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Stamping of Side Panel Using the Laser Welded Tailored Blank (레이저 용접 테일러드 블랭크를 이용한 사이드 패널 성형)

  • 권재욱;명노훈;백승엽;인정제;이경돈
    • Transactions of Materials Processing
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    • v.8 no.1
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    • pp.7-13
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    • 1999
  • In this study, side panels were developed using the laser-welded tailored blank (T.B.) of both the same thickness and different thickness. At first, the formability of the same thickness T.B. was investigated to compare with one of the non-welded panel with respect to weldline movement and strain distribution in blank during the stamping process. Based on these results, we determined the weld line positions and the die step for T.B. forming of the blanks composed of different thickness combination. Then we made some stamping tryouts with selected types of blanks to investigate the formability of T.B. of the different thickness. During the tryouts, wrinkles were found in the a-pillar lower region which is under the deformation mode of the shrink flange. In the b-pillar region, fractures were also found. These defects have been reduced and corrected by controlling the blank design, the die faces and process parameters.

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An Improved Scheme for the Blank Holding Force in Sheet Metal Forming Analysis using the Modified Membrane Finite Element Considering Bending Effect (굽힘이 고려된 개량 박막 유한요소를 사용한 박판금속 성형해석에서의 블랭크 홀딩력 적용방법에 관한 연구)

  • Choi, Tae-Hoon;Huh, Hoon
    • Transactions of Materials Processing
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    • v.8 no.4
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    • pp.347-355
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    • 1999
  • The paper is concerned with an improved scheme for application of the blank holding force in order to take account of the thickness distribution in the sheet material of the flange region. The scheme incorporates with a modified membrane finite element method for planar anisotropic materials. The new scheme proposed two coefficients α and βto calculate the compressive stress in the sheet metal due to the blank holding force, which should be determined properly for accurate analysis. The effect of αand βon the blank holding force distribution and the deformed shape is investigated with simulation of rectangular cup deep drawing processes by changing parameter values.

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A Study on the Optimal Blank Design Using Sensitivity Analysis Method (민감도법에 의한 최적블랭크 형상 설계에 관한 연구)

  • Sim, Hyeon-Bo;Son, Gi-Chan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.1 s.173
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    • pp.79-86
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    • 2000
  • In this study, a method of optimal blank design using the sensitivity analysis has been proposed. To get sensitivity a well-known commercial code PAM-STAMP has been used. In order to verify this method, formings of square cup, clover shaped cup and L shaped cup have been chosen as the examples. With the predicted optimal blank both computer simulation and experiment are performed. Excellent agreements are recognized between the numerical results and the target contour shapes. Through the investigation, the proposed systematic method of optimal blank design is found to be effective in the design of the deep drawing process.

A Study on Initial Blank Design and Modification for Rectangular Case Forming with Extreme Aspect Ratio (세장비가 큰 사각케이스 성형을 위한 초기 블랭크의 설계 및 개선에 관한 연구)

  • 구태완;박철성;강범수
    • Transactions of Materials Processing
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    • v.13 no.4
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    • pp.307-318
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    • 2004
  • Rectangular drawn case with extreme aspect ratio is widely used for electrical parts such as a lithium-ion battery container, semi-conductor case and so on. Additionally, from the recent trend towards miniaturization of the multi-functional mobile device, demands for rectangular case with the narrow width are increased. In this study, numerical and experimental approaches for the multi-stage deep drawing process have been carried out. Based on the research results of the width of 5.95mm model, finite element analysis for storage case of rectangular cup type was verified to the width of 4.95mm. Also, a series of manufacturing experiments for rectangular case is conducted and the deformed configuration of the rectangular drawn case are investigated by comparing with the results of the numerical analysis. And the modification of the initial blank is performed to minimize the trimmed material amount. By the application of the modified blank, the sound shape of the deformed parts is improved.

A Study on Punch Load According to Blank Shape in Elliptical Cup Forming (타원용기 성형에서 블랭크 형상에 따른 펀치하중 변화에 관한 연구)

  • 박동환;허영민;강성수
    • Transactions of Materials Processing
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    • v.10 no.3
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    • pp.235-245
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    • 2001
  • Deep drawing process, one of sheet metal forming methods, is very useful in the industrial field because of its efficiency The deep drawing is affected by many process variables, such as blank shapes, shape radii of the punch and die, formability of materials and so on. Especially, blank shape is very important formability factor. In this study, in order to investigate the effects of blank shape, we suggested three kinds of blank shapes and examined friction test about three conditions. We measured punch load distribution according to punch stroke under the conditions of each punch and die shape radii and observed punch load of elliptical cup forming.

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