• Structural Engineering and Mechanics
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• 제21권3호
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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.

• 한국정밀공학회지
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• 제22권6호
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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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.

• 한국재난정보학회 논문집
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• 제19권3호
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• pp.644-655
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• 2023

연구목적: 금속의 취급 및 가공 공장과 금속폐기물 저장 공장 등에서 금속이 포함된 화재가 빈번하게 발생하고 있다. 금속화재의 경우는 소화가 어렵고 장시간 소요되므로 대응 시 주의가 필요하다. 본 연구에서는 금속화재의 발생 현황과 문제점 등을 제시하고 국내에서 사용중인 간이소화용구와 약제에 대한 실험을 통해 효과성을 도출하였다. 연구방법: ISO7165의 D급소화기 실험 중 분말 형태의 실험을 준용하여 순도 99.9%, 입자 150 ㎛ 이상의 마그네슘을 착화하여 5가지 간이소화용구, 소화기 및 약제에 대한 비교실험을 하였다. 연구결과: 간이소화용구로는 국내에서 가장 많이 사용되는 건조사와 팽창질석, 사용성 검증이 필요한 황토가루를 사용하였고, 국외에서 인증받아 사용중인 D급 소화기와 국내 금속화재 현장에서 사용된 액상의 수산화실리카를 사용하였다. 결론: 본 실험을 통해 소화효과성과 사용편의성, 경제성 측면을 고려한 결과, 팽창질석이 금속 화재 시 가장 적절한 것으로 도출되었다.

• Steel and Composite Structures
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• 제27권2호
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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.

• 한국지반환경공학회 논문집
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• 제12권9호
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• pp.13-20
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• 2011

산지가 많은 우리나라는 도로 및 철도건설을 위해 사면을 형성하는 구간이 많고, 사계절의 뚜렷한 차이로 인해 해빙기에 암블록의 이완현상 발생과 연평균 강우량의 2/3 정도가 여름철에 집중 발생되는 기후특성이 있으며, 최근 기상이변에 따른 집중호우 등으로 낙석 및 산사태와 같은 도로절개면 붕괴사고가 잦은 편이며, 해마다 장마철이 되면 이와 관련된 사고소식을 매스컴을 통해 쉽게 접할 수 있다. 낙석 발생 시 인명과 재산 피해를 최소화하기 위하여 절개지에 대한 보강공법의 개발 및 현장 적용성에 대한 연구 등이 활발히 이루어지고 있지 않는 실정으로 이에 대한 연구의 필요성이 부각되고 있다. 특히 낙석방지망의 부분적 취약점(일체화가 되지 못함)으로 인해 낙석방지망이 충분한 지지능력을 발휘하지 못하는 문제가 발생됨에 따라 국내에서도 보다 높은 낙석에너지를 지지할 수 있는 낙석방지망에 대한 연구가 필요할 것으로 판단된다. 이에 본 연구에서는 낙석방지망의 대체재료로서 팽창메탈의 적용성을 실험적으로 검증하고, 그 특성에 관해 연구해 보고자 하였다. 시험결과 팽창메탈은 우수한 강도와 일체화된 재료특성으로 기존 PVC망에 비해 최대지지하중이 높게 나타났으며, 현장시험의 흡수가능에너지 또한 높게 나타나 낙석방지망의 대체재료로서 활용이 가능한 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제16권4호
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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.

• 한국가구학회지
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• 제24권4호
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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.

• 대한건축학회논문집:계획계
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• 제36권2호
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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.

• Current Optics and Photonics
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• 제3권1호
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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.