• 제목/요약/키워드: R/C beam

검색결과 349건 처리시간 0.026초

수직앵커형 중간철근으로 보강된 고강도 철근콘크리트 보_-기둥 접합부의 소성힌지 확산 (Spreading Beam Poastic Hinging Zone of the High-Strength R/C Beam-Column Joints Using the Vertically Anchored Intermediate Reinforcements)

  • 유영찬;이원호;이리형
    • 콘크리트학회지
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    • 제7권4호
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    • pp.169-179
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    • 1995
  • 본 논문은 고강도 콘크리트($f'_c=700kg/cm^2$)를 사용한 보_기둥 접합부의 소성힌지 확산을 위하여 중간철근을 수직으로 앵커한 수직앵커형 중간철근으로 보 단부를 보강함으로써 보_기둥 접합부에 발생하는 소성힌지를 보 내측으로 1.0d 만큼 확산시키고자 하는 것이다. 실험의 주 변수로는 중간철근의 유물 및 앵커여부로 설정하여 중간철근의 보강형태에 따른 부재의 역학적 거동을 규명하도록 하였다. 실험결과로부터 보 단부의 1.0d부분을 수직앵커형 중간철근으로 보강하면 소성힌지를 1.0d 부분으로 확산할 수 있었으며, 에너지 분산능력도 ACI318-89에 따라 설계한 관례적인 실험체에 비하여 약 1.6배정도 향상되었다.

고강도 철근 및 고강도 콘크리트를 사용한 보-기둥 접합부의 연성거동 (Ductile Behavior of High Strength Reinforced Concrete Beam-Column Joint)

  • 이정한;유영찬;이원호;정헌수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.537-540
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    • 1999
  • The primary objective of this study is to make a contribution to the construction of 40~60 story R/C high rise building by developing the reinforcing details which can improve the seismic performance of high-strength (f'c=700kg/$\textrm{cm}^2$, fy=4000, 8000kg/$\textrm{cm}^2$) R/C beam-column joints. And the purpose of this study is to investigate experimentally the effect of load history on the total energy dissipation capacity of reinforced concrete flexural members. The reinforcing details which can make beam plastic hinging zones moved and spreaded from the column face is proposed to insure the ductile behavior of high-strength RC beam-column joints. The intermediate reinforcement which is horizontally anchored by interlinking each intermediate reinforcements is proposed and tested to examine the mechanical performance of proposed details. Main variables are the shape of the intermediate reinforcements and yield strength of rebars. From the test results, the newly proposed intermediate reinforcement details can move and spread the beam plastic hinging zone about 1.0d from the column face.

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고강도 철근 및 고강도 콘크리트를 사용한 보-기둥 접합의 비선형 거동 (Inelastic Behavior of High Strength Reinforced Concrete Beam-Column Joint)

  • 이정한;조중현;유영찬;이원호;정헌수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.547-552
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    • 1999
  • The purpose of this study is to make a contribution to the construction of 40∼60 story R/C high rise building by developing the reinforcing details which can improve the seismic performance of high-strength (f'c=700㎏/㎠, fy=4000, 8000㎏/㎠) R/C beam-column joints. The reinforcing details which can make beam plastic hinging zones moved and spreaded from the column face is proposed to insure the ductile behavior of high-strength RC beam-column joints. The intermediate reinforcement which is vertically anchored by interlinking each intermediate reinforcements is proposed and tested to examine the mechanical performance of proposed details. Main variables are the shape of the intermediate reinforcements and yield strength of rebars. From the test results, the newly proposed intermediate reinforcement details can move and spread the beam plastic hinging zone about 1.0d from the column face.

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Characteristics of Critical Pressure for a Beam Shape of the Anode Type ion Beam Source

  • Huh, Yunsung;Hwang, Yunseok;Kim, Jeha
    • Applied Science and Convergence Technology
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    • 제27권4호
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    • pp.65-69
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    • 2018
  • We studied the critical pressure characteristics of an anode type ion beam source driven by both charge repulsion and diffusion mechanism. The critical pressure $P_{crit}$ of the diffusion type ion beam source was linearly decreased from 2.5 mTorr to 0.5 mTorr when the gas injection was varied in 3~10 sccm, while the $P_{crit}$ of the charge repulsion ion beam source was remained at 3.5 mTorr. At the gas injection of 10 sccm, the range of having normal beam shape in the charge repulsion ion beam source was about 6.4 times wider than that in the diffusion type ion beam source. An impurity of Fe 2p (KE = 776.68 eV) of 12.88 at. % was observed from the glass surface treated with the abnormal beam of the charge repulsion type ion beam source. The body temperature of the diffusion type ion beam source was observed to increase rapidly at the rate of $1.9^{\circ}C/min$ for 30 minutes and to vary slowly at the rate of $0.1^{\circ}C/min$ for 200 minutes for an abnormal beam and normal beam, respectively.

결속선이 R/C보의 거동에 미치는 영향에 대한 실험적 연구 (An Experimental Study on the Effect of Tie-wire on R/C Beam Behaviors)

  • 변항룡;공귀옥;김준성;이수곤
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.737-742
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    • 1997
  • In this paper the effect of tie wire in lap spliced bars is investigated by experiment. The variables considered in the beam behaviors are beam dimension, lapped splice length and numbers of tie wire. 3 test pieces having the same variables consist one series and a total of 6 series ar tested. The test results show the beam behavior is not affected by numbers of tie wire but by the manner of tie. It was revealed hat the load bearing capacity of the beam is increased when the tie wire is extended to top bar.

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빔 블랑크를 이용한 H 형강 압연 거동 연구 (Analysis of the Metal Flow in H-Beam Rolling using Beam Blank)

  • 김정민;최우남;박춘수;김기원
    • 소성∙가공
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    • 제22권7호
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    • pp.383-388
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    • 2013
  • Metal flow of the beam blank during H-beam rolling was examined in order to correlate the rolling defects with the beam blank configuration. For this purpose, H-beam rolling was performed on the beam blank where stainless steel bolts were inserted as the marker at the web and flange. The positional variation of the marker was monitored at each rolling pass, and the result was compared with the 3D FEM simulation employing the point tracking function. The simulation results were reasonably agreed with the experimental within the error of 0.5~1mm on both web and flange of the H-beam. It is anticipated that the 3D FEM simulation employing the point tracking function provides the guidance information on analyzing the correlation between the rolling defects and the beam blank configuration in H-beam rolling.

Cone-beam computed tomography for the assessment of root-crown ratios of the maxillary and mandibular incisors in a Korean population

  • Choi, Sung-Hwan;Kim, Jung-Suk;Kim, Cheol-Soon;Yu, Hyung-Seog;Hwang, Chung-Ju
    • 대한치과교정학회지
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    • 제47권1호
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    • pp.39-49
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    • 2017
  • Objective: This retrospective, cross-sectional study aimed to establish reference data for normal crown and root lengths and the root-crown ratios (R/C ratios) for the mature maxillary and mandibular incisors in a Korean population by using cone-beam computed tomography (CBCT). Methods: We included 672 Korean patients (141 men and 531 women; mean age, $27.2{\pm}7.7years$) who underwent CBCT examinations during various dental treatments. Crown and root lengths and the R/C ratios of the maxillary and mandibular incisors were measured using CBCT data, which were analyzed to detect significant differences between demographic factors as well as sagittal and vertical skeletal or occlusal relationships. Results: Teeth of the same type in each half-arch were symmetrical. The mean R/C ratios varied from 1.1 to 1.2 for the maxillary incisors and from 1.3 to 1.4 for the mandibular incisors. Crown and root lengths were greater in men than in women, regardless of tooth type. Root lengths and R/C ratios for the mandibular incisors were significantly greater in patients with skeletal Class II malocclusion or an excessive overjet than in the other patients. The R/C ratios for the mandibular incisors were lower in patients with an open bite than in those with a normal or deep bite. Moreover, the R/C ratios for the mandibular incisors increased with age. Conclusions: The data obtained in our study can serve as reference values for crown and root lengths and the R/C ratios for the maxillary and mandibular incisors in the Korean population.

Modeling of nonlinear response of R/C shear deficient t-beam subjected to cyclic loading

  • Hawileh, R.A.;Abdalla, J.A.;Tanarslan, M.H.
    • Computers and Concrete
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    • 제10권4호
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    • pp.419-434
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    • 2012
  • This paper presents a finite element (FE) model for predicting the nonlinear response and behavior of a reinforced concrete T-beam deficient in shear under cyclic loading. Cracking loads, failure loads, response hysteresis envelopes and crack patterns were used as bench mark for comparison between experimental and FE results. A parametric study was carried out to predict the optimum combination of the open and close crack shear transfer coefficients (${\beta}_t$ and ${\beta}_c$) of the constitutive material model for concrete. It is concluded that when both shear transfer coefficients are equal to 0.2 the FE results gave the best correlation with the experimental results. The results were also verified on a rectangular shear deficient beam (R-beam) tested under cyclic loading and it is concluded that the variation of section geometry has no effect on the optimum choice of the values of shear transfer coefficients of 0.2. In addition, a parametric study based on the variation of concrete compressive strength, was carried out on the T-beam and it is observed that the variation of concrete compressive strength has little effect on the deflection. Further conclusions and observations were also drawn.

The Effects of Ion Beam on the Liquid Crystal Alignment Phenomena using a-C:H Thin Films

  • Rho, Soon-Joon;Chung, Doo-Han;Jeon, Baek-Kyun;Kim, Kyeong-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.1114-1117
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    • 2004
  • We investigated the liquid crystal (LC) alignment phenomena using hydrogenated amorphous carbon (a-C:H) thin films. For LC alignment, the surface of a-C:H thin films is treated with low energy ion beam. We investigated the relationship between the properties of a-C:H thin films and LC alignment phenomena.

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강섬유 보강 고강도 철근 콘크리트 보-기둥 접합부의 이력 거동에 관한 연구 (A Study on the Hysteretic Behavior of High Strength Steel Fiber Reinforced Concrete Beam-Column Joint)

  • 오경남;이정한;유영찬;이원호;정헌수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.533-536
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    • 1999
  • The primary purpose of this study is to investigate experimentally the effect of steel fiber reinforcement on the total energy dissipation capacity of R/C flexural members and to make a contribution to the construction of 40~60 story R/C high rise building by developing the new materials and reinforcing details which can improve the seismic performance of high-strength R/C beam-column joints. Experimental research was carried out on 4 type specimen under cyclic loading. Main variables are steel fiber reinforcement, intermediate reinforcements and yield strength of rebars. From the test results, steel fiber reinforcement can improve the ductility of R/C flexural members.

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