• Title/Summary/Keyword: forming elements

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Effects of Alloying Elements on the Microstructure and Mechanical Properties of the Copper Forming Dies (금형소재용 동합금의 미세조직 및 기계적 성질에 미치는 첨가원소의 영향)

  • Bae, Jin-Ho;Park, Chong-Sung;Kim, Myung-Ho
    • Journal of Korea Foundry Society
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    • v.18 no.3
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    • pp.271-274
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    • 1998
  • Effects of Si and Ni addition on the microstructure and mechanical properties of the Cu-12wt.%Al-5wt.%Fe-1wt.%Mn alloy have been investigated experimentally. Microstructure of the as-cast specimen is found to be refined markedly by additions of Ni and Si. By the addition of Ni, volume fraction of the ${\kappa}$ phase is increased, but volume fraction of the ${\gamma}$ phase is decreased. Hardness is increased with the addition of Ni, due to increasing of ${\kappa}$ phase which is harder than ${\gamma}$ phase. However, Charpy impact value is not significally decreased possibly due to the formation of isolate ${\kappa}$ phase.

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A Study on Pao, A Caftan type Subculture Garment in China Nationality (중국소수민족 포의 연구)

  • 정은택;박춘순
    • Journal of the Korean Society of Costume
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    • v.50 no.6
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    • pp.155-162
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    • 2000
  • Classifying the diverse and complex clothing category of nationality subcultures in China is not a simple task. However, summing up, it can be largely classified that clothing of the northern area is long trousers and short skirt. Among the clothing of Nationality in China, especially, Pao(robe: 袍) has its diversity and colorfulness. whose elements forming its each characteristic feature has enough value to be investigated fully in the historical point of view. The conclusions of this study reveals that Pao in nationality subculture in China can possibly be divided into the four types as Qipao(旗袍) in Dongpei area, Mongopao(蒙古袍) in Inner Mongolia, Qiapan in Xinjiang area, and Zangpao in Tibet area. The modes of Qipao and Mongopao are mainly similar in that they have diagonally on the right, stand collar in composition, but Qipao shows its diversity in collar and slashes, and Mongopao also shows diversity in its colare and waistband. Since western culture flowed into China along with its open door and reform policy, the splendid color and distinctive pattern, decoration, diversified method of compositions and clothing categories of Nationality cultures are disappearing in its their originality and nationality.

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Correlation of damage and analysis of R/C building: Experience from the 1995 Kobe earthquake

  • Matsumori, Taizo;Otani, Shunsuke
    • Structural Engineering and Mechanics
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    • v.6 no.8
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    • pp.841-856
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    • 1998
  • During the 1995 Hyogoken-Nanbu Earthquake, a reinforced concrete building, called Jeunesse Rokko, suffered intermediate damage by forming a beam-yielding (weak-beam strong-column) mechanism, which has been regarded as the most desirable earthquake resisting mechanism throughout the world. High cost to repair damage at many beam ends and poor appearance expected after the repair work made the owner decide to tear down the building. Nonlinear earthquake response analyses were conducted to simulate the behavior of the building during the earthquake. The influence of non-structural members was considered in the analysis. The calculated results were compared with the observed damage, especially the location of yield hinges and compression failure of spandrel beams, and the degree of cracking in columns and in column-girder connections.

A Study on the Organic Concept of Frank Lloyd Wright's Architecture and Furniture Design (프랭크 로이드 라이트의 건축과 가구디자인의 유기성 연구)

  • Baik, Eun;Lee, Hyun-Jung
    • Journal of the Korea Furniture Society
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    • v.20 no.2
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    • pp.154-165
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    • 2009
  • Frank Lloyd Wright is an architect who established the concept of organic architecture and in his organic architectures, he applied studies on the inflow, growth and development of natural elements of shapes, pursued naturalism in the shapes and functions and connected them organically with each other. His furniture as appeared in his constructions shows geometric plasticity based on naturalism and achieves an integration of shapes, materials and functions while forming a space. The organic nature from the viewpoint of digital which is a new concept of the 21st century is greatly affecting construction and furniture designs. Designs having new organic concepts are emerging in furniture which is organically related with construction to achieve organic harmony with new plastic spaces. Therefore, studies on Wright are more significant as a cornerstone for new theories under development.

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An analysis of the wrinkling initiation in sheet metal forming using bifurcation theory (분기좌굴이론을 이용한 박판성형공정에서의 주름발생해석)

  • 김종봉;양동렬;윤정환
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.03a
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    • pp.28-31
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    • 1998
  • Wrinkling is one of the major defects in sheet metal products and may be also attributable to the wear of the tool. The initiation and growth of the wrinkles are influenced by many factors such as stress state, mechanical properites of the sheet material, geometry of the body, and contact condition. It is difficult to analyze the wrinkling initiation and growth considering the factors because the effects of the factors are very complex and the wrinkling behavior may show wide variation for small deviation of the factors. In this study, the bifurcation theory is introduced for the finite element analysis of wrinkling initiation and growth, All the above mentioned factors are conveniently considered by finite element method. The finite element formulation is based on the incremental deformation theory and elastic-plastic material modeling. The finite element analysis is carried out using the continuum-based resultant shell elements considering the planar anisotropy of the sheet metal. The proposed method is verified by employing to column buckling problem. And then, the initiation and growth of wrinkling in deep drawing of cylindrical cup are analyzed.

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A Study of Saekdong for Modernistic Expressions (색동의 현대적 표현을 위한 연구)

  • 배천범
    • Journal of the Korean Society of Costume
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    • v.47
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    • pp.161-170
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    • 1999
  • In the East color is deeply related to man's feelings or emotional status. This is relevant to the peculiar naturalistic thoughts of the East and concretely speaking is based upon the idea of Yin Yang and Five Elements that has dominated the spiritual world of the East. We can see costumes of the Three Kingdoms era or Koryo dynasty on the murals of ancient tomb presume their social backgrounds through remains of the past and find out the existence of Saekdong. Chosun dynasty shows a wonderful growth of fashion not only in dress but also in such accessories as patchwork wrapping-cloth and Saekdong which imply a lot on formation or color arrangement. Saekdong which we can see throughout many Eastern countries is a representative image that has been forming and expressing our race's color emotions for a long time. Saekdong to become worldwidely used. And this study has attempted modernistic expressions with Saekdong.

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A Study on Thermostable Property of High Density Graphites Products with Expanded Graphite(1) (고밀도 팽창흑연 성형품의 내열 특성에 관한 연구(1))

  • Shin, Y.W.
    • Journal of Power System Engineering
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    • v.9 no.4
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    • pp.148-154
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    • 2005
  • Thermostable property is one of most important characteristics of graphite. Commercial graphites sheet from expanded graphite is using for high-temperature elements. Nowadays the new plant with high performance is developed in field of chemical industries, so the need of graphites is increasing rapidly. In this paper, the thermostable properties of newly developed graphite products with high density is investigated. I introduced the graphite material which developed for these heat tests by NGF method in order to test thermostable properties by comparing to the results of the commercial graphite sheet from expanded graphite in same condition. Through measuring the weight reducing ratio with various specimens in some conditions, I investigated the thermostable characteristics of these materials. It is verified that the graphite products by NGF method has almost same or superior thermostable properties comparing with that of commercial graphite sheet. Also the graphite products by NGF method have possibility of being better in thermostable properties.

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Experimental Verification of Equivalent Drawbead Model and Application to Auto-Body Stamping Analysis (등가 드로비드 모델의 실험적 검증 및 차체 스탬핑 해석에 적용)

  • Moon, S.J.;Lee, J.Y.;Keum, Y.T.
    • Transactions of Materials Processing
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    • v.18 no.5
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    • pp.371-376
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    • 2009
  • An equivalent drawbead model(EDM) for sheet metal forming analysis, which replaces complex drawbead geometries with drawbead forces in modeling the stamping dies with finite elements, is experimentally verified and applied to the numerical simulation of auto-panel stamping process. The drawbead restraining and opening forces of elliptical drawbead, circular drawbead, square drawbead, and step drawbead are obtained by performing the drawbead pulling test and compared with those of EDM and commercial code models(CCM). Better agreement with experimental measurements is found in EDM than CCM. Furthermore, the excellence of EDM is demonstrated in its application to the auto-body stamping analysis.

High-temperature Oxidation of Ni-based Inconel 713 Alloys at 800-1100℃ in Air (니켈기 인코넬 713합금의 800-1100℃에서의 대기중 고온산화)

  • Lee, Dong-Bok
    • Journal of the Korean institute of surface engineering
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    • v.44 no.5
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    • pp.196-200
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    • 2011
  • The Ni-based superalloy, Inconel 713, was oxidized at $800{\sim}1100^{\circ}C$ for 50 and 100 hours in air. It displayed excellent oxidation resistance, forming a few micrometer-thick scales. The major scale was ${\alpha}-Al_2O_3$. Other scales formed were $TiO_2$, $NiAl_2O_4$ and $Cr_2O_3$. Generally, uniform oxidation occurred over the alloy surface, resulting in the formation of ${\alpha}-Al_2O_3$ with and without $Cr_2O_3$. Other oxides such as $TiO_2$ and $NiAl_2O_4$ sometimes also formed. Locally, nodular oxidation occurred at the nodules that consisted of diverse alloying elements. The scales were adherent at $800^{\circ}C$. However, they spalled a little at $900{\sim}1100^{\circ}C$.

VeKo25Cr: A Corrosion and Wear Resistant Powder Metallurgical Alloy with a Basic Hardness of 52 HRC

  • Hofer, Beat W.;Saner, Michel
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.942-943
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    • 2006
  • To meet the demands for use in extremely abrasive and corrosive environments, a new material was developed. The VeKo25Cr distinguishes itself through specifically selected amounts of carbon and carbide forming elements such as Cr, Mo, V, W and Nb. The alloy is based on a Fe matrix. The strength after heat treatment and the wear and corrosion properties are compared to those of other materials. VeKo25Cr can be combined with easy-to-process materials such that the difficult handling is minimized to those places on the piece most subjected to operational wear.

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