• Title/Summary/Keyword: Design and Fabrication

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Feasibility study on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell

  • Chung, Myungjin;Kim, Jongmin;Kim, Jin-Kook
    • Steel and Composite Structures
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    • v.32 no.5
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    • pp.571-582
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    • 2019
  • This study aimed to assess the feasibility on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell. First, 5-m-wide and 15-m-long 9%Ni steel plates were test manufactured from a steel mill and specimens taken from the plates were tested for strength, toughness, and flatness to verify their performance based on international standards and design specifications. Second, plates with a thickness of 10 mm and 25 mm, a width of 4.8~5.0 m, and a length of 15 m were test fabricated by subjecting to pretreatment, beveling, and roll bending resulting in a final width of 4.5~4.8 m and a length of 14.8m with fabrication errors identical to conventional plates. Third, welded specimens obtained via shield metal arc welding used for vertical welding of inner tank shell and submerged arc welding used for horizontal welding were also tested for strength, toughness and ductility. Fourth, verification of shell plate material and fabrication was followed by test erection using two 25-mm-thick, 4.5-m-wide and 14.8-m-long 9%Ni steel plates. No undesirable welding failure or deformation was found. Finally, parametric design using wide and long 9%Ni steel plates was carried out, and a simplified design method to determine the plate thickness along the shell height was proposed. The cost analysis based on the parametric design resulted in about 2% increase of steel weight; however, the construction cost was reduced about 6% due to large reduction in welding work.

Decomposition-based Process Planning far Layered Manufacturing of Functionally Gradient Materials (기능성 경사복합재의 적층조형을 위한 분해기반 공정계획)

  • Shin K.H.;Kim S.H.
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.3
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    • pp.223-233
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    • 2006
  • Layered manufacturing(LM) is emerging as a new technology that enables the fabrication of three dimensional heterogeneous objects such as Multi-materials and Functionally Gradient Materials (FGMs). Among various types of heterogeneous objects, more attention has recently paid on the fabrication of FGMs because of their potentials in engineering applications. The necessary steps for LM fabrication of FGMs include representation and process planning of material information inside an FGM. This paper introduces a new process planning algorithm that takes into account the processing of material information. The detailed tasks are discretization (i.e., decomposition-based approximation of volume fraction), orientation (build direction selection), and adaptive slicing of heterogeneous objects. In particular, this paper focuses on the discretization process that converts all of the material information inside an FGM into material features like geometric features. It is thus possible to choose an optimal build direction among various pre-selected ones by approximately estimating build time. This is because total build time depends on the complexity of features. This discretization process also allows adaptive slicing of heterogeneous objects to minimize surface finish and material composition error. In addition, tool path planning can be simplified into fill pattern generation. Specific examples are shown to illustrate the overall procedure.

Ceramic Green Sheet and Sintering Properties on Solvent Mixture Rate of Electrolyte for Solid Oxide Fuel Cells Fabrication (유기 용매 혼합비에 따른 고체산화물 연료전지 전해질 지지체용 세라믹 그린 시트성형 및 소결 특성)

  • Moon, Bong-Hwa;Lee, Kyung-Min;Lim, Kyoung-Tae;Lee, Chung-Hwan;Lee, Heun-Young;Yoon, Jung-Rag
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.6
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    • pp.426-430
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    • 2012
  • The properties of green sheet were investigated in order to understanding an effects of organic solvent mixture ratio for solid oxide fuel cells fabrication. The purpose of this work is to optimize the slurry condition using the design of experiment to improve green sheet properties. The elongation increased with increasing amount of binder and solvent. With increasing amount of solvent, the air permeability increased but the tensile strength decreased. The best properties of the green sheet appeared amount of the binder 17 wt%, solvent 35 wt% and powder 48 wt%. The optimum condition of green and sintered density for solid oxide fuel cells fabrication was obtained in the sample pressured at 800 $kgf/cm^2$.

Fabrication of 3D-Printed Circuit Device using Direct-Write Technology (Direct Write 기술을 이용한 3DCD의 제작)

  • Yun, Hae Young;Kim, Ho Chan;Lee, In Hwan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.2
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    • pp.1-8
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    • 2016
  • Generally, electrical circuits are fabricated as Printed Circuit Boards (PCBs) and mounted on the casing of the product. Additionally, this requires many other parts and some labor for assembly. Recently, molding technology has increasingly been applied to embed simple circuits in plastic casing. The technology is called a Molded Interconnected Device (MID). By using this technology, PCB fabrication can be replaced by molding, and much of the corresponding assembly process for PCBs can be eliminated if the circuit is simple enough for molding. Furthermore, as the improvement of conductive materials and printing technologies of simple electric circuits can be printed directly on the casing part, this also reduces the complexity of the product design and production cost. Therefore, this paper introduces a new MID fabrication process using direct 3D printing technology. Additionally, it is applied to an automotive part of a cruise control switch. The methodology and design are shown.