• Title/Summary/Keyword: Redrawing

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Nursing Students' Observation Experiences During Operations (간호대학생의 수술관찰경험)

  • Kim, Mi Hee;Ha, Mi Ok
    • Journal of Korean Biological Nursing Science
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    • v.20 no.3
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    • pp.159-168
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    • 2018
  • Purpose: This study aimed to explore nursing students' experiences of observing surgeries in the operating room. Methods: The data were collected through written scripts of nursing students who participated in the operating room practice. Data were analyzed via qualitative content analysis. Results: Five themes emerged from the data: 'preparing with the thrilled hearts toward unknown area', 'drawing back in front of the mirror of realities', 'becoming an audience at a lifesaving orchestra', 'reaching a tipping point of knowing', and 'redrawing the trajectory of dream to be a nurse'. Conclusion: This study will prove helpful in describing their needs for systemic and emotional support. Findings indicated that major contributions of surgical observations to nursing students are more integrated understandings of nursing and the determinations of their career preferences.

FE Analysis on Doming & Necking Process of Steel D&I Can (Steel D&I Can의 Doming 및 Necking 공정의 FEM 해석)

  • Jung, S.W.;Nam, J.B.;You, C.S.;Jin, Y.S.;Han, K.S.
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.452-457
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    • 2000
  • The object of this study is to develop a reliable FEM simulation technique for the analysis of can making process using PAM-STAMP software. The processes consist of doming and necking in addition to drawing, redrawing. After body making process, this study analyzed the stability for internal pressure by simulating buckling test. Through these technique, we estimated the dome reversal pressure of steel D&I Can for various can profile and process conditions. From this study, we found the cause and mechanism of wrinkling during necking process. This mechanism is largely affected by can wall thickness and the clearance between knock out punch and necking die. The dome reversal pressure improves with increasing dome depth. These results validate the usefulness of the developed simulation technique for the analysis of body making process and optimization of the dome profile.

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A Study on the Acoustic Transmission Characteristics of Polygon Accumulator (다각형 Accumulator의 음향 특성 연구)

  • Seo, Won-Sik;Kong, Byung-O;Kim, Young-Ho;Nam, Kyeong-Hun
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.5
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    • pp.653-661
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    • 2009
  • In order to reduce the noise and oscillation, it is consider a matter in all aspects about the noise stem from accumulator and the characteristic of transmission, Transformation of outside shape has change of noise occurrence at transmission process. Therefore, performed sound numerical analysis and conducted an experiment to examine the birthplace of accumulator's external shape change. In a sound numerical analysis, we can fond out transmission loss between inlet and outlet's sound pressure. In an experiment, we can make out transmission loss by sound wave separation theory through drawing sound pressure inlet and outlet.

Influence of Process Design Scheme on Product Qualities in Cylindrical Cup Drawing (원형컵 드로잉의 공정설계 변화에 따른 제품품질에 미치는 영향)

  • 이재명;이상민;최영윤;류호연;김종호
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.82-85
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    • 2002
  • A systematic investigation for process design in deep drawing is necessary for quality improvement of drawn cups. This study has been concentrated mainly on the influence of process design scheme on product qualities in cylindrical cup drawing. Three types of process design scheme were chosen in this study. That is, Case 1 is to finish drawing a cup of 50m in diameter in one stage, Case 2 and Case 3 are redrawing the drawn cups of 55, 65 mm in diameter to the final size respectively. Though experiments the maximum drawing force in two-stage cup drawing could be reduced up to 35% as compared with that of one-stage cup drawing. In addition, the Case 2 and Case 3 processes showed better product qualities than the Case 1 process when comparing distributions of thickness, hardness, dimensional accuracy.

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Influence of Process Design Scheme on Product Qualities in Cylindrical Cup Drawing (원형컵 드로잉의 공정설계 변화가 제품품질에 미치는 영향)

  • 이재명;김종호;원시태
    • Transactions of Materials Processing
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    • v.11 no.8
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    • pp.716-723
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    • 2002
  • A systematic investigation for the process design in deep drawing is necessary to improve the quality of drawn cups. This study concentrates mainly on the influence of process desing scheme on the product qualities in cylindrical cup drawing. Three types of process design scheme were chosen in this study. Case 1 is to draw a finished cup of 50mm in diameter in one stage, Case 2 and Case 3 are redrawing the first drawn cups of 55, 65mm in diameter to the final size respectively. Through experiments the maximum drawing force in two-stage cup drawing can be reduced up to 24% as compared with that of one-stage cup drawing. In addition, Case 3 process results in better product qualities than the other two processes in terms of the distributions of thickness and hardness.

A Study on the Process Improvements of the Multi-stage Deep Drawing by the Rigid-plastic Finite Element Method (강소성 유한요소법을 이용한 다단계 디프드로잉의 공정개선에 관한 연구)

  • 전병희;민동균;김형종;김낙수
    • Transactions of Materials Processing
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    • v.3 no.4
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    • pp.440-453
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    • 1994
  • The multi-stage deep-drawing processes including normal-drawing, reverse-drawing, and re-drawing are analyzed by use of the rigid-plastic finite element method. Computational results on the punch/die loads and thickness distributions were compared with the experiments of the current drawing processes. Deep-drawing processes of the redesigned shell to improve the specific strength and stiffness were simulated with the numerical method developed. With varying several process parameters such as blank size, corner radii of tools, and clearances, the simulation results showed the improvements in reducing the forming loads. Also forming defects were found during simulation and appropriate blank size could be verified.

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A Study on the Process Analysis of Multi-Stage Deep Drawing (다단계 디프드로잉의 공정해석에 관한 연구)

  • 심재진;전병희;김낙수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.12
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    • pp.2936-2948
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    • 1993
  • Multi-stage deep drawing is an important sheet metal forming process. The deformation mechanisms of sheet metals during forming processes are complicated mainly due to the geometry and the lubrication of tools involved, the formability and the anisotropic behaviour of the material. The multi-stage deep-drawing processes including normal-drawing, reverse-drawing, and re-drawing are analyzed by use of the rigid-plastic finite element method. The anisotropic behaviour represented by r-value can be incorporated into the formulation. Punch/die loads and thickness distributions were obtained as results of simulating axisymmetric deep drawing processes. The computed results showed good agreements with experiments.

The Applicatiion of Finite Element Method to Process Design Considering Forming Limit in Deep Drawing (성형한계를 고려한 디프 드로잉 공정설계에 대한 유한 요소 해석)

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    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.06a
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    • pp.74-82
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    • 1998
  • The limit drawing ratio (LDR) is a major process parameter in the process design of deep drawing. If the actual drawing ratio is greater than the LDR for a particular stage, then an intermediate stage has to be added to the process sequence to avoid failure during the ratio. In this study, the optimal process design considering forming limit is performed for the first-drawing and redrawing by using finite element method combined with ductile fracture criterion. The LDR and the site of fracture initiation are predicted by means of the fracture criterion. From the results of finite element analysis, the optimal value of drawing ratio is obtained, which contributes to the more uniform distribution of thickness and the smaller values of the ductile fracture in final cup.

The Application of Finite Element Method to Process Design Considering Forming Limit in Deep Drawing (성형한계를 고려한 디프 드로잉 공정설계에 대한 유한 요소 해석)

  • Choe, Yeong;Lee, Gyu-Ho;Go, Dae-Cheol;Kim, Byeong-Min;Choe, Jae-Chan
    • Transactions of Materials Processing
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    • v.7 no.6
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    • pp.562-569
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    • 1998
  • The limit drawing ratio (LDR) is a major process parameter in the process design of deep drawing. If the actual drawing ratio is greater than the LDR for a particular stage then an intermediate stage has to b added the process sequence to avoid failure during the drawing operation and the optimal process design considering for the first-drawing and redrawing by using finite element method combined with ductile fracture criterion. From the results of finrte element analysis the optimal value of drawing ratio is obtained which contributes to the more uniform distribution of thickess and the smaller values of the ductile fracture infinal cup.

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Multi-scale Image Segmentation Using MSER and its Application (MSER을 이용한 다중 스케일 영상 분할과 응용)

  • Lee, Jin-Seon;Oh, Il-Seok
    • The Journal of the Korea Contents Association
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    • v.14 no.3
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    • pp.11-21
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    • 2014
  • Multi-scale image segmentation is important in many applications such as image stylization and medical diagnosis. This paper proposes a novel segmentation algorithm based on MSER(maximally stable extremal region) which captures multi-scale structure and is stable and efficient. The algorithm collects MSERs and then partitions the image plane by redrawing MSERs in specific order. To denoise and smooth the region boundaries, hierarchical morphological operations are developed. To illustrate effectiveness of the algorithm's multi-scale structure, effects of various types of LOD control are shown for image stylization. The proposed technique achieves this without time-consuming multi-level Gaussian smoothing. The comparisons of segmentation quality and timing efficiency with mean shift-based Edison system are presented.