• Title, Summary, Keyword: Expanded metal

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Seismic shear strengthening of R/C beams and columns with expanded steel meshes

  • Morshed, Reza;Kazemi, Mohammad Taghi
    • Structural Engineering and Mechanics
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    • v.21 no.3
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    • pp.333-350
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    • 2005
  • This paper presents results of an experimental study to evaluate a new retrofit technique for strengthening shear deficient short concrete beams and columns. In this technique a mortar jacket reinforced with expanded steel meshes is used for retrofitting. Twelve short reinforced concrete specimens, including eight retrofitted ones, were tested. Six specimens were tested under a constant compressive axial force of 15% of column axial load capacity based on original concrete gross section, $A_g$, and the concrete compressive strength, ${f_c}^{\prime}$. Main variables were the spacing of ties in original specimens and the volume fraction of expanded metal in jackets. Original specimens failed before reaching their nominal calculated flexural strength, $M_n$, and had very poor ductility. Strengthened specimens reached their nominal flexural strength and had a ductility capacity factor of up to 8 for the beams and up to 5.5 for the columns. Based on the test results, it can be concluded that expanded steel meshes can be used effectively to strengthen shear deficient concrete members.

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

  • Jung Chang Gyun;Yoon Seok-Joon;Lee Sang Min;Na Suck-Joo;Lee Sang-hoon;Ahn Dong-Gyu;Yang Dong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6
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    • pp.175-182
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    • 2005
  • 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.

Experimental and numerical study on energy absorption of lattice-core sandwich beam

  • Taghipoor, Hossein;Noori, Mohammad Damghani
    • Steel and Composite Structures
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    • v.27 no.2
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    • pp.135-147
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    • 2018
  • Quasi-static three-point bending tests on sandwich beams with expanded metal sheets as core were conducted. Relationships between the force and displacement at the mid-span of the sandwich beams were obtained from the experiments. Numerical simulations were carried out using ABAQUS/EXPLCIT and the results were thoroughly compared with the experimental results. A parametric analysis was performed using a Box-Behnken design (BBD) for the design of experiments (DOE) techniques and a finite element modeling. Then, the influence of the core layers number, size of the cell and, thickness of the substrates was investigated. The results showed that the increase in the size of the expanded metal cell in a reasonable range was required to improve the performance of the structure under bending collapse. It was found that core layers number and size of the cell was key factors governing the quasi-static response of the sandwich beams with lattice cores.

A Study on the Evaluation of Expanded Metal Characteristics for Application Rockfall Facilities (낙석방지시설 적용을 위한 팽창메탈의 특성 연구)

  • Lee, Jong-In;Jung, Chun-Gyo;Kim, Sung-Ho;Hwang, Yeong-Cheol;Lee, Seung-Ho
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.9
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    • pp.13-20
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    • 2011
  • There are many mountains in Korean Peninsula, and those used for the construction of roads and railways sectors are forming slopes. Slope collapse occurs with falling rocks and landslide because of the relaxation of the thawing rocks. The heavy rain in summer can also significantly contribute to the process, and abnormal climate change is much more influential than before. Therefore, rockfall-related accidents in rainy season are easily accessible in media every year. There has been a lot of research on application of strengthening compensation of the sections in order to minimize casualties and property damage. Rockfall Protection Net, however, has not been focused on much in the field yet. This study highlights the need of Rockfall Protection Net, since it can segregate the falling rocks inside the net relatively safely. Although there has been a little doubt about the effectiveness of rockfall protection facilities, it is obvious that relevant studies dealing with the solidity of the net are necessary for the rockfall protection net to be capable of supporting rockfall energies. As a result, Expanded metal strength is much more durable compared to the PVC coating net, and it is regarded as an excellent alternative material for the Rockfall Protection Net. In this study, the applicability of Expanded Metal as the alternative of Rockfall Protection Net is verified experimentally.

Metal Ion-Containing Langmuir-Blodgett Films of a Monooctadecyl Itaconate Copolymer

  • 손종현;최기선;이범종;Kazue Kurihara
    • Bulletin of the Korean Chemical Society
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    • v.16 no.4
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    • pp.316-320
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    • 1995
  • The incorporation of metal ion into the Langmuir-Blodgett (LB) film of an itaconate copolymer was investigated. The polymer was prepared via radical copolymerization of monooctadecyl itaconate with triethyleneglycol methyl vinyl ether. The metal ions employed were Na+, Cs+, Mg2+, Fe2+, Al3+, and Fe3+. The surface pressure-area isotherms indicated that all the monolayers studied on subphases with metal ions showed more expanded areas than that observed on pure water. The monolayers showed an irreversible collapse behavior. The collapse pressure of the monolayers was low on subphases containing trivalent metal ions. From the FT-IR spectra by reflection and transmission modes, the formation of carboxylate salts and the uprisen orientation of the pendant against substrate surface in the polymer LB film were determined. It was estimated by XPS measurement that ca. 13.1 repeat units of the polymer contain one Na+ ion, while one Mg2+ ion corresponds to 5.9 carboxyls.

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Interior Office Space, Furniture Design Trends Study - Metal Furniture Design from the 1960s to the Present Formative Characteristics of the Center - (실내 사무 공간 가구디자인 경향에 관한 연구 - 1960년대부터 현재까지 금속가구디자인 조형적 특성 중심으로 -)

  • Yang, Woo-Chang;Kim, Myeong-Tae
    • Journal of the Korea Furniture Society
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    • v.24 no.4
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    • pp.329-344
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    • 2013
  • Metal furniture design in this study from the 1960s to the present period of office space by Metal furniture design Metal furniture for social factors in the development. In other words, social and economic characteristics, and the country's formative characterize metal office furniture design characteristics and the development of culture is to provide an opportunity to understand. The scope of this study, including the development of office automation in the 1960s, causing a drastic change in the world at the time of furniture developed in Germany, Italy, the United States, Japan, and examine each country's furniture and metal furniture from the 1960s to the present design trends in office organize, and research methods literature and various data classification by age and by extracting the key trends are established form. The results of this study and the design tends to obscure the distinction between two different aspects of the design appear rarely common or different forms of expression are characterized by two. This furniture range has expanded to use metal and metal to minimize the negative aspects of a conventional flexible image is designed to suit the tastes of modern design and metal furniture design, interior space, except that now it is considered that the most can be identified.

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A Study on the Ornamental Metal Used in the Roof of Ancient Architecture in Korea (고대 건축의 지붕부에 사용된 금속장식에 관한 연구)

  • Youn, Lily
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.2
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    • pp.63-70
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    • 2020
  • In the ancient Buddhist temple area, various metal artifacts are still excavated. Therefore, the aim of this study is to approach the characteristics of ancient architecture through ancient metal artifacts. First, metal decoration of ancient architecture appears for the purpose of structure, decoration, arson. Then, as the method of wood structure is developed, the application is separated into structural, functional and decorative purposes. In ancient times, metal decoration has reduced the role of structure, but its decorative role has expanded. Second, various metallic ornaments were used on the roof of ancient architecture. As the wooden technology developed, the metal decoration was gradually omitted while applying the curve to the roof. Third, the metal ornaments used on the roof of ancient architectures include the ridge central decoration, roof top decoration, a nine-ring decoration, gable board Ornamental Metal, corner flower decoration, eaves nail, wind bell. And subsequent research requires a terminology that can link the results of archeology and Buddhist art through excavation as a result of architecture.

Tuning Photoluminescence of Biological Light Emitters via Silk Protein Based Resonators

  • Arif, Sara;Umar, Muhammad;Kim, Sunghwan
    • Current Optics and Photonics
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    • v.3 no.1
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    • pp.40-45
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    • 2019
  • Adding tunability to biological light emitters offers an unprecedented technique in biological sensing and imaging. Here, we report a tunable, lithographic-free, planar, and ultrathin metal-insulator-metal (MIM) resonator capable of tuning the optical properties solely by a silk/sodium fluorescein hydrogel layer, a biocompatible light emitter. In water, the volume of the resonator was expanded by swelling, and then the resonant mode could be shifted. Simulations predicted the red-shifted resonance peak in transmission when the MIM was swollen in water. The red-shift could be attributed to the increase in the thickness of the silk hydrogel layer due to the absorbed water. The shift of the resonance could affect the fluorescence of the dye in the silk hydrogel layer.

Filler effect of inner-structure bonded sheet metal in shearing process (내부구조재를 가진 중공형 접합판재의 전단가공특성에서 틈새효과에 관한 연구)

  • Kim, Ji-yong;Jung, Wan-jin;Kima, Jong-ho
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.2 no.1
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    • pp.15-19
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    • 2008
  • While recent industrial structure is various, it is small quantity batch production structure, and products requiring of various functions are increasing. 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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