• Title, Summary, Keyword: 준 정적 실험

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Evaluation of Seismic Performance for an Internally Confined Hollow CFT Column (내부 구속 중공 CFT 기둥의 내진 성능 평가)

  • Han, Taek Hee;Kim, Sung Nam;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.19 no.1
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    • pp.53-65
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    • 2007
  • Column tests were performed for a new type of column, the internally confined hollow concrete filled tube column (ICH CFT column), to evaluate its seismic performance. The seismic performances for two types of ICH CFT columns and a general solid RC column were evaluated and compared by quasi-static tests. The displacements and the lateral loads of column specimens were measured during tests. Ductilities, absorbed energy, equivalent damping ratios, damage indices were calculated from recorded data. From the test results, the ICH CFT column shows superior seismic performances with double moment capacity and larger energy absorbing capacity over that of a solid RC column.

Performance Assessment of Precast Segmental PSC Bridge Columns Considering P-delta effects (P-delta 영향을 고려한 프리캐스트 세그먼트 PSC 교각의 성능평가)

  • Kim, Tae-Hoon;Park, Se-Jin;Kim, Young-Jin;Shin, Hyun-Mock
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.4
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    • pp.45-54
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    • 2008
  • The purpose of this study was to investigate the performance of precast segmental PSC bridge columns with regard to P-delta effects. A model of precast segmental PSC bridge columns was tested under a constant axial load and a cyclically reversed horizontal load. A computer program, RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), was used for the analysis of reinforced concrete structures. In addition to the material nonlinear properties, an algorithm for the problem of large displacement that may result in additional deformation has been formulated using total Lagrangian formulation. This study documents the testing of precast segmental PSC bridge columns under cyclic loading, and presents conclusions based on the experimental and analytical findings.

A Efficient Scheduling Study about Periodic and Aperiodic Task on Real-Time System (실시간 시스템에서 주기 및 비주기 태스크의 효율적인 스케줄링 연구)

  • Ko, Guk-Hee;Lee, Sung-Jun;Ahan, Kang-Sun
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.1757-1760
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    • 2003
  • 실시간 시스템에서 주기 태스크의 마감시간을 보장하며 도착 시간을 예측할 수 없는 비주기 태스크를 처리되도록 스케줄링 하는 것은 매우 중요하다. 본 논문에서는 정적 우선순위 스케줄링 방식 중 최적인 RM방식으로 주기 태스크를 스케줄링하고, 비주기 태스크의 발생시 비주기 태스크를 EDF 방식으로 스케줄링하여 오프라인에서 구한 슬랙을 비주기 태스크에 할당한다. 제안한 방식은 비주기 태스크의 마감시한내의 슬랙과 비주기 태스크의 실행 시간을 비교하여 비주기 태스크가 마감시한 내에 실행되지 못하는 경우 주기 태스크와 슬랙을 최적적합으로 교환하는 방식을 사용하여 비주기 태스크의 처리를 가능하게 하였다. 제안된 방식은 경성 비주기 태스크와 연성 비주기 태스크에 적용이 가능하며, 실험 결과 교환 알고리즘을 적용한 스케줄링 방식이 적용하지 않은 스케줄링 방식에 비해 비주기 태스크의 처리율이 높게 나왔다.

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Quasi Static Test of Lap Spliced Shear-Flexure RC Piers Using Real Scale Models (주철근 겹침이음된 휨-전단 RC교각의 실물모형 준정적 실험)

  • 곽임종;조창백;조정래;김영진;김병석
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.203-210
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    • 2002
  • The past bridge design specifications of Korea didn't include 1imitation on the amount of lap splices in the plastic hinge zone of piers, and so do current specifications. But these specifications include just limitation on the minimal length of lap splices. Thus, a large majority of non-seismically designed bridge piers may have lap splices in plastic hinge zone. In this study, model pier was selected among existent bridge piers whose failure mode is complex shear-flexure mode. Full scaled RC pier models whose aspect ratio is about 2.67 were constructed and quasi static test according to the drift level history was implemented. From the test results, effect of the lap splices on the seismic performance of bridges piers was analyzed, and the seismic capacity of the model bridges was evaluated by capacity spectrum method.

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Research of Plastic response by Quasi-Static Test for Circulr Hollow R.C. Bridge Pier (준정적 실험에 의한 중공원형 콘크리트 교각의 소성응답 연구)

  • 정영수
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.247-255
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    • 1999
  • Because of relatively heavy dead weight of concrete itself and unavoidable heat of massive concrete in bridge piers circular hollow columns are widely used in Korean highway bridges Since the occurrence of 1995 Kobe earthquake there have been much concern about seismic design for various infrastructures inclusive of bridge structures. It is however understood that there are not much research works for nonlinear behavior circular hollow columns subjected to earthquake motions. The ultimate of this experimental research is to investigate nonlinear behavior of hollow reinforced concrete bridge piers under the quasi-static cyclic load test and than to enhance their ductility by strengthening the plastic hinge region with glassfiber sheets. It can be concluded from Quasi-static test for 7 bridge piers that approximate 4-5 ductility factor can be experimentally obtained for bridge piers nonseismically designed in conventional way which approximate 5-6 ductility factor for those seismically designed.

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Quasi-Static Tests for seismic performance of RC bridge piers (철근콘크리트 교각의 내진성능에 관한 준정적 실험)

  • 이강균;한기훈;정영수;이대형;황의승
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.615-620
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    • 1998
  • The objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete piers subjected to quasi-static cyclic loads, which have been used in large numbers for railway and urban transportation facilities. Important test parameters are hoop ratio, axial load, loading type, and the behaviors f members have been evaluated through limit states of crack occurrence, yielding and ultimate state of member, ductility and load-deflection loop can be secured by considering the influence of hoop reinforcement ratio and axial load, and that plastic hinge length and ductility ar determined by the combination of the quantities of hoop reinforcement and axial load.

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Crashworthiness Improvement of Idealized Vehicle's Side Rails (이상화된 자동차 측면부재의 충돌특성 향상에 관한 연구)

  • 김흥수;박신희;강신유;한동철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.2
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    • pp.189-197
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    • 1996
  • In this study, the crashworthiness analysis was carried out for the hat type section side rails which had an important role of absorbing the impact energy during frontal crash. In case of a tapered hat type section model, numerical simulation models and test models were designed with varing design variables; welding pitch, taper angle, initiator shape, initiator location. The effect of variation of the design variables was investigated by quasi-static and dynamic test and numerical simulation.

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AC PDP의 셀 크기 및 격벽 높이 변화에 따른 방전 특성 분석

  • Lee, Jong-Bong;Sim, Seung-Bo;Choe, Yong-Seok;Hwang, Seok-Won;Lee, Ho-Jun;Lee, Hae-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.106-106
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    • 2010
  • AC PDP(Plasma Display Panel)는 상압에 가까운 압력에서 DBD(Dielectric Barrier Discharge) 방전을 이용한 디스플레이다. AC PDP는 보통 면 방전을 이용하기 때문에 대향 방전과는 다른 방전 현상을 보인다. 본 연구에서는 4인치 test 패널 제작하여 격벽 높이 변화에 따른 방전 현상을 연구하였다. PDP 셀은 $1mm^3$ 보다 작은 크기를 가지고 있기 때문에 방전 현상을 분석하는 것은 쉽지 않다. 그래서 이 연구에서는 2, 3차원 유체 시뮬레이션을 이용하여 실험 결과에 대한 방전 현상을 연구하였다. 테스트 패널을 통하여 정적 마진, 휘도, 소비전력, 발광효율 등을 구하였고, Fluid 시뮬레이션을 통하여 전기장 분포, 하전입자 및 여기종 입자들의 개수 및 밀도 분포, 벽전하 분포 등을 통하여 방전 특성의 경향성을 분석하였다. 격벽 높이가 높아질수록 방전 공간이 넓어지면서 효율이 증가하였으나 $140\;{\mu}m$ 이상의 높이에서는 광 변환 효율이 감소하면서 효율이 오히려 감소하였다.

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Seismic Retrofit of RC Columns with Lap-Spliced Longitudinal Rebars Wrapping by SMA Wires (SMA Wire를 이용한 주철근 겹침이음된 RC 교각의 내진 보강 연구)

  • Park, Yong-Kwon;Lee, Yeon-Hun;Yang, Dong-Wook;Lim, Hyeon-Sik;Chung, Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.129-130
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    • 2010
  • Lap splice of longitudinal reinforcing steels was located in the plastic hinge region of most bridge piers that had been designed and constructed before the adoption of the 1992 seismic design provision of Korea Highway Design Specification. This research aims at improving the seismic performance of reinforced concrete bridge piers with lap-spliced longitudinal steels, of which the plastic hinge region was wrapped by the shape memory alloy (SMA) wires. Quasi-static test was used to investigate the seismic behaviours of RC test specimens.

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Quasi-Static Test for Seismic Performance of Circular R.C. Bridge Piers Before and After Retrofitting (유리섬유 보강 원형 철근콘크리트 교각의 내진성능에 관한 준정적 실험연구)

  • 정영수;이강균;한기훈;이대형
    • Journal of the Korea Concrete Institute
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    • v.11 no.5
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    • pp.107-118
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    • 1999
  • 10 RC bridge piers have been made on a 1/3.4 scale model, and six piers of them were retrofitted with glassfiber. The have been tested in the quasi-static cyclic load so as to investigate their seismic enhancement before and after retrofitting with glassfibers. The objective of this experimental study is to investigate how to strength the ductility of reinforced concrete bridge piers which have been nonseismically designed and constructed in Korea before 1992. Important test parameters are axial load, load pattern, retrofit type. Glassfiber sheets were used for retrofitting in the plastic hinge region of concrete piers. The nonlinear behavior of bridge columns have been evaluated through their yield and ultimate strength, energy dissipation, displacement ductility and load-deflection characteristics under quasi-static cyclic loads. It can be concluded from the test that concrete piers strengthened with glassfibers have been enhanced for their ductile behavior by approximate 50%.