• Title, Summary, Keyword: Expanded metal

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Mechanical Behavior of Sandwich Panels with Quasi-Kagome Truss Core Fabricated from Expanded Metals (확장금속망을 이용하여 제작된 준카고메 트러스 중간층을 갖는 샌드위치 판재의 기계적 거동)

  • Lim, Chae-Hong;Lim, Ji-Hyun;Jung, Jae-Gyu;Lim, Jong-Dae;Kang, Ki-Ju
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.9
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    • pp.1078-1085
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    • 2006
  • Many studies have been focused on how to manufacture ultra light metal structures and optimize them. In this study, we introduced a new idea to make sandwich panels with quasi-Kagome truss cores. First, metal sheets with a peculiar pattern of slits were expanded to be meshes, they are crimped into a triangular wave pattern, and then one third of struts were bent reversely to be quasi-Kagome trusses. Finally, two face sheets were bonded on the upper and the lower sides. The bending strength was estimated through elementary mechanics for the sandwich specimens with two kinds of face sheet the results of estimation were compared with the those of finite element analyses and experiments.

A Study on the Shear Deformation Behavior of Inner Structure-Bonded sheet metal (접합판재의 전단 변형거동에 관한 연구)

  • Kim J. Y.;Kim J. H.;Chung W. J.;Yang D. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.33-38
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    • 2004
  • In order to improve the quality of the sheared surface in cutting of inner structure bonded sheet metal the cut-off operation is mainly investigated, which is the typical shearing process in sheet metal forming technology. The sandwich sheet metals considered have inner structure which is constructed in the form of crimped expanded metal and woven metal. The inner structure is bonded between solid sheet by resistance welding or adhesive bonding. The shearing process is visualized by the computer vision system installed in front of the cut-off die and the sheared surface is measured and quantitatively compared with the help of the optical microscope after cut-off operation. From test results we found that the influence of sheared position can be observed and explained clearly and this result can be utilized to get the better sheared surface.

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A Study on the Forming Characteristic of Inner Pyramid Structure Bonded Sheet Metal (피라미드형 내부구조재를 가지는 중공형 접합판재의 성형특성에 관한 연구)

  • Kim, J.Y.;Kil, H.Y.;Cho, G.C.;Kim, J.H.;Chung, W.J.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.295-299
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    • 2006
  • The inner-structure bonded(ISB) sheet metal is defined as a composite sheet metal which has middle layer of truss-structure between two skin sheets. The characteristics such as ultra-light weight, high rigidity, high strength, etc are required especially for automobile parts. The characteristic of ISB sheet metal depends on inner-structure pattern or method of bonding. Pyramid type of crimped expanded metal is used for inner-structure and both of resistance welding and adhesive bonding are applied to make a specimen. As a result of compression test, it is appeared that forming limit is 10% reduction in thickness under a load of 8kgf per unit element(one inner-structure). In case of uniaxial tensile test the non-uniform surface integrity rather than the buckling of inner-structure happened at a load of 450kgf, which indicates elongation of 7.2% and thickness reduction of 13%. The eye-inspection method was applied to examine the defects occurring on the specimen during stretch forming. In case of biaxial stretch forming only the non-uniform deformation on the surface of a skin sheet could be observed. The forming limit in stretching of ISB sheet metal with the hemi-spherical punch of 150mm in diameter was 3mm in forming depth and 5% reduction in thickness.

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Fabrication and Static Bending Test in Ultra Light Inner Structured and Bonded(ISB) Panel Containing Repeated Inner Pyramidal Structure (피라미드 구조를 가지는 초경량 금속 내부구조 접합판재의 제작 및 특성평가)

  • 정창균;윤석준;성대용;양동열;안동규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.483-486
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    • 2004
  • Inner structured and bonded panel, or ISB Panel, as a kind of sandwich type panel, has metallic inner structures which have low relative density, because of their dimensional shape of metal between a pare of metal skin sheets or face sheets. In this work, ISB panels and inner structures formed as repeated pyramidal shapes are introduced. Pyramidal structures are formed easily with expanded metal sheet by the crimping process. Three kinds of pyramidal structures are made and used to fabricate test specimen. Through the multi-point electrical resistance welding, inner structures are bonded with skin sheet. 3-point bending tests are carried out to measure the bending stiffness of ISB panel and experimental results are discussed.

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Development and Performance Evaluation of the Expanded Metal Rockfall Protection Fence

  • Hwang, Young-Cheol;Kim, Bum-Joo;Noh, Heung-Jae
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.3
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    • pp.35-45
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    • 2005
  • The rockfall protection fence is one of the most common rockfall protection methods in Korea. The typical rockfall protection fence consists mainly of three parts ; H-beam supports, wire meshes, and wire ropes. The design of the rockfall protection fence is made such that the total energy absorbing capacity of the fence. Therefore, resulting from the combined energy absorbing capacity of the three parts is larger than the falling energy of rocks. In present study, a new rockfall protection fence, constructed using expanded metals instead of the existing wire rope and wire mesh for the typical type of rockfall protection fence, was evaluated on its performance by conducting both laboratory and field tests. Also, for a comparison, the same tests were performed on the typical rockfall protection fence. The test results revealed that the expanded material is an economic alternative to the existing protection materials and the expanded metal rockfall protection fence exhibits the higher energy absorbing capacity compared to that of the typical rockfall protection fence.

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Investigation into Characteristics of Bending Stiffness and Failure for ISB Panel (ISB 판넬의 굽힘강성 및 파손특성에 관한 연구)

  • Ahn Dong-Gyu;Lee Sang-Hoon;Kim Min-Su;Han Gil-Young;Jung Chang-Gyun;Yang Bong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.9
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    • pp.162-172
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    • 2005
  • The objective of this research works is to investigate into characteristics of bending stiffness and failure for the ISB ultra-lightweight panel with internally structured material. The expanded metal with a crimped pyramid shape and woven metal are employed as an internally structured material. Through three-points bending test, the force-displacement curve and failure shape are obtained to examine the deformation pattern, characteristic data, such as maximum load, displacement at maximum load, etc, and failure pattern of the ISB panel. In addition, the influence of design parameters fur ISB panel on the specific stiffness, the specific stiffness per unit width, failure mode and failure map has been found. Finally, it has been shown that ISB containing expand metal with the crimped pyramidal shape is prefer to that containing woven metal from the view point of optimal design for ISB panel.

An Estimation for Efficiency of Expanded Metal for Rockfall Protection Fences (팽창메탈형 낙석방지울타리의 개발 및 성능 평가)

  • Hwang, Young-Cheol;Lee, Seung-Ho;Noh, Heung-Jea;Woo, Sang-Baek;Shin, Ju-Yul
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.153-162
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    • 2005
  • The structural specification of the rockfall prevention fence installed on the road section is computed according to the hypothetic rockfall energy, and the absorbable energy of the rockfall prevention fence is defined as the sum of the absorption energies of the wire rope, one of the components, the steel support and the wire netting. But the results of the field tests confirmed that the absorption energy of the rockfall prevention fence is not the sum of the energies sustainable by the components, but it is affected by the absorbable energy of part of the components. This shows there are problems with the method of computing the absorption energy of the rockfall prevention fence of the road. So in this paper, as a way of solving the problems, the effects of improving the performance through positional changes of the existing components and the effects of improving the performance through structural changes by expanded metal are checked through tests, and a plan was proposed to solve the problems with the standards of installing the conventional rockfall prevention fence.

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Influence of Metallic Sodium on Repair Weldability for Type 316FR Stainless Steel

  • Chun, Eun-Joon;Lee, Su-Jin;Suh, Jeong;Lee, Ju-Seung;Kang, Namhyun;Saida, Kazuyoshi
    • Journal of Welding and Joining
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    • v.35 no.1
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    • pp.79-88
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    • 2017
  • The effect of residual metallic sodium on the solidification cracking susceptibility of type 316FR stainless steel was investigated via transverse-Varestraint tests. And a solidification brittle temperature range (BTR) of type 316FR stainless steel was 37 K. However, the BTR expanded from 37 to 67 K, as the amount of metallic sodium at the specimen surface increased from 0 to $7.99mg/cm^2$. Microstructural observation of the weld metal suggested that metallic sodium existed in the weld metal, including in the cell boundaries, during welding solidification. Thermodynamic calculations suggested that sodium expanded the temperature range of solidliquid coexistence during welding solidification of the steel weld metal. Therefore, the increased solidification cracking susceptibility (i.e., expansion of the BTR) in the residual sodium environment was attributed to enhanced segregation of sodium during the welding solidification; this segregation, in turn, resulted in an expanded temperature range of solid-liquid coexistence.

A Study on the Removal of an Heavy Metal Ions by an Functional Nano Fibers (기능성 나노섬유에 의한 중금속 이온의 제거에 관한 연구)

  • An Hyung-Hwan
    • Journal of the Korean Society of Safety
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    • v.19 no.3
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    • pp.57-64
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    • 2004
  • This is the study for the removal of a toxic heavy metal ions and the recycling of expanded polystyrene wastes. Thus expanded polystyrene wastes collected from the packing materials of TV or chemicals and dissolved by $80wt.\%$ solvent(N, N-Dimethylacrylamide), electrospun in DC 20kV by power supply. Generally, the electrospinning is a process of manufacture to the fibers of nanosize from polymer solution. Manufactured nanofiber mats by electrospinning were sulfonated by cone.-sulphuric acid with $Ag_2S_O_4$ catalysts for the exchange capacity of heavy metal ions and the properties of structure with sulfonated time investigated by FESEM(Feild Emission Scaning Electron Microscope). The ion exchange capacity of light metal$(Na^+)$, Cd(II) and Ni(II), and by a nanofiber mats were 1.94[mmo1/g-dry-mat), 1.72(mmol/g-dry-mat), 1.24(mmol/g-dry-mat), respectively., and water uptake content showed a similar trend with IEC. and The selectivity coefficients $K^M_H$ of Cd(II), Ni((II) ions showed 0.324, 0.228. respectively.

Simultaneous dry-sorption of heavy metals by porous adsorbents during sludge composting

  • Ozdemir, Saim;Turp, Sinan Mehmet;Oz, Nurtac
    • Environmental Engineering Research
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    • v.25 no.2
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    • pp.258-265
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    • 2020
  • Heavy metal removal by using porous mineral adsorbents bears a great potential to decontaminate sludge compost, and natural zeolite (NZ), artificial zeolite (AZ), and expanded perlite (EP) seem to be possible candidates for this purpose. A composting experiment was conducted to compare the efficiency of those adsorbents for removal of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), and lead (Pb) from sewage sludge compost with no adsorbent amendment. For this purpose, 10 g of NZ and AZ and 5 g of EP was filled in a small bag made from non-biodegradable synthetic textile and was separately mixed in composting piles. The bags were separated from compost samples at the end of the experiment. AZ and NZ exhibited different reduction potentials depending on the type of heavy metal. AZ significantly reduced Cr (43.7%), Mn (35.8%), and Fe (29.9%), while NZ more efficiently reduced Cu (24.5%), Ni (22.2%), Zn (22.1%), and Pb (21.2%). The removal efficiency of EP was smaller than both AZ and NZ. The results of this simultaneous composting and metal removing study suggest that AZ and NZ can efficiently bind metal during composting process.