• Title/Summary/Keyword: R/C beam

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Seismic performance of exterior R/C beam-column joint under varying axial force

  • Hu, Yanbing;Maeda, Masaki;Suzuki, Yusuke;Jin, Kiwoong
    • Structural Engineering and Mechanics
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    • v.78 no.5
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    • pp.623-635
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    • 2021
  • Previous studies have suggested the maximum experimental story shear force of beam-column joint frame does not reach its theoretical value due to beam-column joint failure when the column-to-beam moment capacity ratio was close to 1.0. It was also pointed out that under a certain amount of axial force, an axial collapse and a sudden decrease of lateral load-carrying capacity may occur at the joint. Although increasing joint transverse reinforcement could improve the lateral load-carrying capacity and axial load-carrying capacity of beam-column joint frame, the conditions considering varying axial force were still not well investigated. For this purpose, 7 full-scale specimens with no-axial force and 14 half-scale specimens with varying axial force are designed and subjected to static loading tests. Comparing the experimental results of the two types of specimens, it has indicated that introducing the varying axial force leads to a reduction of the required joint transverse reinforcement ratio which can avoid the beam-column joint failure. For specimens with varying axial force, to prevent beam-column joint failure and axial collapse, the lower limit of joint transverse reinforcement ratio is acquired when given a column-to-beam moment capacity ratio.

Novel Patterning of Gold Using Spin-Coatable Gold Electron-Beam Resist

  • Kim, Ki-Chul;Lee, Im-Bok;Kang, Dae-Joon;Maeng, Sung-Lyul
    • ETRI Journal
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    • v.29 no.6
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    • pp.814-816
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    • 2007
  • Conventional lithography methods of gold patterning are based on deposition and lift-off or deposition and etching. In this letter, we demonstrate a novel method of gold patterning using spin-coatable gold electron-beam resist which is functionalized gold nanocrystals with amine ligands. Amine-stabilized gold electron beam resist exhibits good sensitivity, 3.0 mC/$cm^2$, compared to that of thiol-stabilized gold electron beam resists. The proposed method reduces the number of processing steps and provides greater freedom in the patterning of complex nanostructures.

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Experimental study on strengthening of R.C beam using glass fibre reinforced composite

  • Mini, K.M.;Alapatt, Rini John;David, Anjana Elizabeth;Radhakrishnan, Aswathy;Cyriac, Minu Maria;Ramakrishnan, R.
    • Structural Engineering and Mechanics
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    • v.50 no.3
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    • pp.275-286
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    • 2014
  • This paper reports the influence of number of layers and length of GFRP sheets wrapped onto RCC beams for strengthening. Twelve beams of size $700mm{\times}150mm{\times}150mm$ were cast and tested. Two beams without GFRP and ten beams wrapped in different lay-up patterns with one and two layers of GFRP sheets was subjected to three point loading test and ultrasonic pulse velocity test. Initial crack load, ultimate failure load and types of failure have been observed and noted. Experimental results indicate a significant increase in initial and ultimate load carrying capacity of GFRP wrapped beams compared to unwrapped beams. The failed control specimen was retrofitted using U wrap scheme and tested under three point loading.

A thermal properties of micro hot-plate fabricated by using the Pt/Cr bilayer (Pt/Cr 이중층을 이용한 미세 발열체의 제작과 발열특성)

  • Yi, Seung-Hwan;Suh, Im-Choon;Sung, Yong-Kwon
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1982-1984
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    • 1996
  • In this paper, we have evaluated the physical characteristicsof the Pt/Cr bilayer, fabricated the micro hot plate by using the Pt/Cr bilayer and E-beam evaporated oxide as a passivation layer, and simulated the thermal distribution by using the commercial software FIDAP. From the researches the sheet resistance of Pt/Cr bilayer didn't be affected by the Cr layer thickness. This results was considered due to the Cr-oxide resided at the interface between Pt and Cr layer. After manufacturing the hot plate, we measured its temperature by type k thermo-couple and I.R. thermo-vision system. In those experiments, the emission coefficient( ${\varepsilon}$ ) of the E-beam evaporated oxide was 0.5 and the temperature of centural region was reached about $305\;^{\circ}C$ at 1.3 watts. The temperature simulation obtained by FIDAP commercial package stewed that the temperature of centural region was about $311\;^{\circ}C$ after 5 sec.

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A Study on the Moment Resisting Performance of the Hybrid Beam-Column Connection System with Structural Tee (T 형강을 사용한 합성골조 보-기둥 접합부의 휨 저항성능에 관한 연구)

  • 임대성;최광호;김상식
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.597-602
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    • 1998
  • The composite systems, consisting of R/C Columns-Steel Beams, are reasonable structures because of their constructional and economical advantages, workability and so on. But, it is difficult to apply the composite systems to actual design due to material dissimilarity and complicate stress flow in the connection. This study aims to propose the hybrid beam-column connection system with structural tee and through experimental research make clear the shear and moment resistance capacity and stress transfer mechanism.

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Cyclic performance of steel fiber-reinforced concrete exterior beam-column joints

  • Oinam, Romanbabu M.;Kumar, P.C. Ashwin;Sahoo, Dipti R.
    • Earthquakes and Structures
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    • v.16 no.5
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    • pp.533-546
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    • 2019
  • This study presents an experimental investigation on six beam-column joint specimens under the lateral cyclic loading. The aim was to explore the effectiveness of steel fiber-reinforced concrete (SFRC) in reducing the transverse shear stirrups in beam-column joints of the reinforced concrete (RC) frames with strong-columns and weak-beams. Two RC and four SFRC specimens with different types of reinforcement detailing and steel fibers of volume fraction in the range of 0.75-1.5% were tested under gradually increasing cyclic displacements. The main parameters investigated were lateral load-resisting capacity, hysteresis response, energy dissipation capacity, stiffness degradation, viscous damping variation, and mode of failure. Test results showed that the diagonally bent configuration of beam longitudinal bars in the beam-column joints resulted in the shear failure at the joint region against the flexural failure of beams having straight bar configurations. However, all SFRC specimens exhibited similar lateral strength, energy dissipation potential and mode of failure even in the absence of transverse steel in the beam-column joints. Finally, a methodology has been proposed to compute the shear strength of SFRC beam-column joints under the lateral loading condition.

Structural Performance Evaluation of Slab-Beam-Column Subassemblage in R/C Ordinary Moment Frame Building (철근콘크리트 보통모멘트 골조의 슬래브-보-기둥 부재의 구조성능 평가)

  • 유혁상;한상환;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.757-762
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    • 2000
  • The purpose of this study is to investigate the performance of slab-beam-column subassemblage in the Ordinary Moment Frame(OMF). For this purpose, 3-story building was designed according to UBC and ACI building code(ACI 318-99) and the subassemblages of in the first story were constructed. The subassemblages were classified into interior and exterior. Each interior and exterior subassemblage is modeled by the 2/3 scale experimental specimens. All the specimens have the transverse beam and the columns on the slab have the lap splice as the typical exterior and interior slab-beam-column subassemblage. The interior subassemblage was tested under the constant axial force, while the exterior subassemblage was tested under the fluctuating axial force. Based on the results of the experiments, the performance of each subassemblage is evaluated and the failure mode is investigated.

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Measurement of Bremsstrahlung Radiation with Electron Beam Energy

  • Srivastava, R.P.;Chaurasia, P.P.;Prasiko, G.;Jha, A.K.
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.235-236
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    • 2002
  • A Klystron powered dual photon energy electron linear accelerator 2300 C/D from Varian Associates has been installed in our center. From the radiological safety view as well as treatment planning, the output (contamination) of Bremsstrahlung Radiation with electron beam energy determined accurately. It has been found 0.5% to 4.7% with increasing the electron beam energy which is the clinically not much significant in the treatment of the malignant diseases with the treatment of electron beam.

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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.