• 제목/요약/키워드: Drawing Test

검색결과 543건 처리시간 0.025초

컵드로잉에 의한 판재의 마찰특성 평가 (A Cup Drawing Test for Measuring the Coefficient of Friction in Sheet Metal Forming)

  • 김영석;최원집
    • 한국자동차공학회논문집
    • /
    • 제2권1호
    • /
    • pp.96-105
    • /
    • 1994
  • Cup drawing tests were performed to evaluate the friction characteristics of sheet metals. The linear relationship between drawing force and blank holding force obtained from the cup drawing test was used to calculate the coefficient of friction of the sheet metal. The friction coefficient was compared to that from conventional draw bead friction test. It was clarified that the cup drawing test can be used as a simple and convenient method for evaluating the friction characteristic of the sheet metal and also lubricity of the lubricant used.

  • PDF

치매선별검사로서의 시계 그리기 검사(CDT)에 관한 기초연구 (The Pilot study of Clock Drawing Test as a screening test for dementia)

  • 김광호;임재환;김종우;황의완;조성훈
    • 동의신경정신과학회지
    • /
    • 제12권2호
    • /
    • pp.185-191
    • /
    • 2001
  • Objectives: This study aimed to evaluate the usefulness as a screening test of Clock Drawing Test(CDT) compared with the standard K-DRS in probably dementia. Methods: The subjects for this study consisted of 19 elderly persons who visited to the outpatient department of Oriental Neuropsychiatry of the Kyunghee Oriental hospital. They received the K-DRS and the Clock Drawing Test. Three observers evaluated them with circle, numbers, hands. Inter-rater reliability of scores from Clock Drawing Test was assessed and Pearson correlation coefficients were used to examined the relationships between scores from Clock Drawing Test and K-DRS. Results: Correlations between individual raters was highly significant (r= .957, .974, and .970, respectively: p<.001). There was stastically significant correlations between K-DRS and CDT scores (r= 0.849, p<.001). Conclusions: The CDT can be rated reliably by observers and correlations between CDT and K-DRS is significantly high. We confirmed the usefulness of CDT as simple, easily administered, low cost, and reliable general screening test for dementia.

  • PDF

공작기계 주축 테이퍼 결합부 정강성에 관한 연구 (A Study on the Static Stiffness in the Main Spindle Taper of Machin Tool)

  • 김배석;김종관
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
    • /
    • pp.149-154
    • /
    • 2001
  • This paper presents the experimental study of the static stiffness for the BT Shank(7/24 Long Taper) and the HSK Tool Shank(1/10 Short taper). The static stiffness test was performed under different experimental conditions. The results obtained are as follows ; As known in the analysis results of the Load-Deflection diagram of the 7/24 Test tool shank, it is turned out that the diagram is a linear characteristics without regard to axial drawing force and according as the axial drawing force get to the 6kN, the static stiffness of the shank increase linearly. Thus the effective axial drawing force which maintains the static stiffness of the Main spindle taper of Machine Tool is larger than 6kN. It is found that the Load-Deflection diagram with 6kN of drawing force in the 1/10 Test tool shank is characterized by non-linear. But according as the axial drawing force is increasing by the 8kN, the diagram is characterized by linear. And increasing amount of deflection is about 60%. Therefore commendable axial drawing force is larger than 8kN. As a result, considering that the actual drawing force of the Machining Center is about 1300kgf and axial drawing force 12kN is equivalent amount as a 1220kgf, it is turned out that 1/10 Test tool shank superior to 7/24 Test tool shank in the static stiffness.

  • PDF

돌기 튜브 성형을 위한 회전 금형 인발공정에 관한 연구 (Drawing Process with Rotational Die for Forming Grooves in a Tube)

  • 박준홍;변상민
    • 한국기계가공학회지
    • /
    • 제17권4호
    • /
    • pp.123-129
    • /
    • 2018
  • A rotational drawing die which can form a long tube with spiral grooves on the surface is presented. The main feature of the proposed die is a rotation insert that is embedded into the die container for the die to freely rotate with respect to the drawing centerline as the materials are drawn. We employed a three-dimensional finite element model to investigate the effects of the rotational die on the material filling of spiral grooves. The material used in the finite element analysis was stainless 304. We also performed a pilot drawing test to verify the usefulness of the proposed rotational drawing die. Results reveal that the material filling of spiral grooves by the proposed rotational drawing die was in good agreement for both the finite element analysis and the drawing test. We found that the underfill in a conventional drawing die was reduced in the proposed rotational drawing die.

피복된 판재의 성형 특성에 관한 실험적 연구 (An Experimental Study on the Forming Characteristics of Pre-Coated Metals)

  • 김호윤;왕신일;배원병
    • 소성∙가공
    • /
    • 제9권5호
    • /
    • pp.463-468
    • /
    • 2000
  • An experimental study has been performed to investigate the forming characteristics of pre-coated metals(PCMs) widely used in domestic appliances through Erichsen tests and deep drawing tests. Erichsen tests are performed to find out the forming limits of seven pre-coated metals in normal conditions. Rectangular deep-drawing tests are carried out to know the effects of die materials and blank metals on forming loads and surface defects of final PCM products. In the deep-drawing test, four die materials [STD11(TiCN), STD11, STD11(TD), AMPCO] are used. In the Erichsen test, the forming limits of PCMs are obtained from flaking or crack of pre-coated films and lower than those of base metals. In respect of surface roughness and forming load, STD11(TD) and AMPCO materials are superior to my other die-materials used in the deep-drawing test.

  • PDF

변형모드별 판재의 마찰특성 비교 (Comparison of Friction Coefficients of Sheet Materials in Various Deformation Modes)

  • 김영석;김기수
    • 소성∙가공
    • /
    • 제3권1호
    • /
    • pp.51-62
    • /
    • 1994
  • Cup drawing test and U-bending test were performed to evaluate the friction characteristics of sheet materials for the different deformation modes involved in stamping process. The coefficient of friction calculated from the each test was compared to that obtained from the draw bead friction test. It was clarified that the cup drawing test could be simply used for evaluating the friction characteristic of sheet material in deep drawing process with high contacting pressure. However the U-bending test is suitable to evaluate the frictional characteristic of sheet material in bending process with low contacting pressure.

  • PDF

노인의 죽음불안과 별-파도 그림 반응특성에 관한 탐색적 연구 (An Exploratory Study on the Elderly's Anxiety Towards Death and their Reactions to the Star-Wave Drawing)

  • 최외선;박인전
    • 가정과삶의질연구
    • /
    • 제25권5호
    • /
    • pp.15-29
    • /
    • 2007
  • The purposes of this study were to examine if there is a relationship between elderly people's anxiety towards death and their reactions to the Star-Wave drawing, and to verify if the Star-Wave drawing was a good enough tool to measure elderly people's degree of death anxiety. The subject for this study were 307 elderly people (male 127, female 180) over 60 years of age with no physical and cognitive damage, who were residing in Geongsan city and attending colleges or welfare centers for the aged. The collected data were analyzed with SPSS WIN(ver. 12.0) program, and factor analysis, correlation analysis, Chi-square test, t-test, one-way ANOVA, and $Scheff\acute{e}$ test were utilized. The results showed that factors showing different levels of anxiety towards death in the Star-Wave drawing were the total harmony of the drawing, drawing style, repetition of wave, size of the star, and location of the star. In particular, the group that drew the Star-Wave drawing with total harmony felt less anxiety towards death than the other group. Therefore, the results of this study suggested a possibility of the Star-Wave drawing to be used as a good tool that could diagnose the elderly's degree of anxiety towards death.

디지털 기기에서의 그림검사를 위한 Application 개발 연구 (A Study on the Application Development for the Drawing Test)

  • 김선희;김선주
    • 한국콘텐츠학회논문지
    • /
    • 제21권2호
    • /
    • pp.707-717
    • /
    • 2021
  • 본 연구는 디지털기기에서 앱을 활용한 그림검사가 가능한지를 탐색해보고자 게임 중독군을 대상으로 '나무에서 사과 따는 사람 그리기(Person Picking an Apple from a Tree: 이하 PPAT)' 그림 검사를 바탕으로 진단을 확인하여 미술치료에서의 그림검사 앱을 활용할 수 있는 근거를 마련할 수 있는지를 살펴보는데 목적이 있다. PPAT 그림검사는 사람이 사과를 어떤 식으로 따는지 문제해결력을 검증하는데 유용하고 이에 대한 신뢰도, 타당도가 높은 검사이다. 본 연구를 통해 살펴본 결과, 디지털 기기에서 앱을 활용한 PPAT 그림검사의 형식척도(Formal Elements Art Therapy Scale:이하 FEATS) 항목 14개 중 '문제해결력' 항목에서 인터넷 과몰입군이 일반사용자군 보다 낮은 점수를 받았는데, 과몰입군의 경우 사과를 향해 손을 뻗지 않고 있거나, 사과가 떨어지는 그림, 합리적인지지 기반 없이 사과를 따는 방법으로 사과를 따른 모습을 표현했다. 본 연구에서 발견한 내용은 디지털 기기에서 앱을 사용한 PPAT 그림 검사가 본래의 목적인 '문제해결력'을 유의미하게 드러내었다는 점은 앞으로 디지털 기기를 활용하여 인터넷 과몰입 대상자들을 위한 심리치료적 개입뿐만 아니라 디지털 기기를 익숙하게 활용하는 사용자들에게는 PPAT 그림검사 앱을 활용할 수 있다는 점에서 연구의 의의가 있다.

온간금형에 의한 클래드판재(STS304-A1050-STS304)의 드로잉성 연구 (A Study on the Drawability of Clad Sheet Metal (STS304-A1050-STS304) by Warm Draw Die)

  • 류호연;김종호;류제구
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2002년도 금형가공 심포지엄
    • /
    • pp.136-143
    • /
    • 2002
  • Warm draw die technique which is one of the new forming technologies to improve formability of sheet metal is applied to the cylindrical and square cup drawing of stainless-aluminum clad sheets. In experiments the temperature of die and blank holder is varied from room temperature to $180^{\circ}C$, while the punch is cooled by circulation of coolant to increase the fracture strength of workpiece on the punch comer area. Test materials chosen for experiments are STS304-A1050-STS304 clad sheets. Teflon film as a lubricant is used on both sides of a workpiece. The limit drawing ratio and relative drawing depth as well as quality of drawn cups(distribution of thickness)are investigated and validity of warm drawing process is also discussed. No separation between each laminated material after drawing occurred through inspection by microscope as well as application of penetrant remover and bond strength test. Therefore, warm forming technique was confirmed to give better results in deep drawing of stainless clad sheet metal.

  • PDF

공작기계 주축 테이퍼 결합부 정강성에 관한 연구 (A Study on the Static Stiffness in the Main Spindle Taper of Machine Tool)

  • 김배석;김종관
    • 한국공작기계학회논문집
    • /
    • 제10권6호
    • /
    • pp.15-20
    • /
    • 2001
  • This paper presents the experimental study of the static stiffness for the BT shank(7/24 long taper) and the HSK tool shank(1/10 short taper) in the main spindle taper of machine tool. The static stif71ess test was performed under different experimental conditions. It is turned out that the effective axial drawing force is larger than 6kN in the 7/24 test tool shank and BkN in the 1/10 test tool shank. As a test result, considering that the actual drawing force of the machining center is about 1300k2f and axal drawing force 12kN is equivalent amount as a 1220kgf, it is turned out that 1/10 test tool shank superior to 7/24 test tool shank in the static stiffness.

  • PDF