• 제목/요약/키워드: pseudo-ductile

검색결과 22건 처리시간 0.019초

Analysis of Mechanical Properties in Steel Frame with Ductile Connections

  • Han, Minglan;Wang, Shuai;Wang, Yan
    • 국제강구조저널
    • /
    • 제18권4호
    • /
    • pp.1464-1469
    • /
    • 2018
  • Steel frames with ductile connections have good seismic performance under strong earthquake, they are now popular for high seismic design. In order to simplify the process of numerical analysis of the steel frames with ductile connections, simplified connection models are introduced, two types of springs are placed in the simplified connection model, which can simulate deformation of the panel zone and members. 6-story-3-bay steel frames with ductile connections are simplified and carried out modal analysis, fundamental periods of the frames predicted by finite-element analysis for simplified steel frame models were compared to the results for actual frame models. 2-story steel frame with reduced beam section connections is simplified and carried out pseudo-static analysis, hysteretic curves and skeleton curves of the frame obtained by finite-element analysis for simplified steel frame model are compared to test results. The comparison show that the difference between them is small, it is reliable and effective to predict mechanical properties of the steel frame with ductile connection by finite-element analysis of simplified steel frame model.

Evaluation on Seismic Performance of Limited Ductile RC Bridge Piers by Pseudo-Dynamic Test

  • Chung, Young-Soo;Park, Jong-Heob;Cho, Chang-Beck;Seo, Joo-Won
    • KCI Concrete Journal
    • /
    • 제13권2호
    • /
    • pp.3-9
    • /
    • 2001
  • Pseudo dynamic test for seven circular RC bridge piers has been carried out to investigate their seismic performance subjected to expected artificial earthquake motions. The objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete bridge piers, which have been widely used for railway and urban transportation facilities. Important test parameters are confinement steel ratio, and input ground motion. The seismic behavior of circular RC bridge piers under artificial ground motions has been evaluated through displacement ductility, cumulative energy input, and dissipation capacity. It can be concluded that RC bridge piers designed in a limited ductile behavior provision of Eurocode 8 have been determined to show good seismic performance even under moderate artificial earthquakes.

  • PDF

유사연성 하이브리드 FRP 시트를 이용한 RC 보의 휨 보강 (Pseudo-Ductile Hybrid FRP Sheet for Strengthening Reinforced Concrete Beams)

  • 하상수;최동욱;이진용;김길희
    • 콘크리트학회논문집
    • /
    • 제20권2호
    • /
    • pp.239-247
    • /
    • 2008
  • 철근콘크리트 휨 부재 보강에 자주 사용하는 탄소섬유 대신 탄소섬유 및 유리섬유 두 가지를 동시에 사용, 보강된 콘크리트 휨 부재의 강도 및 연성을 증진시키는 방안을 연구하였다. 두 가지 섬유의 혼합비가 적절한 경우, 탄소섬유가 선파단하고 보다 큰 변형 및 응력에서 유리섬유가 순차적으로 파단하는 소위 유사연성거동을 보일 수 있다. 본 연구에 사용된 두 가지 섬유가 유사연성거동을 보일 수 있는 이론적인 혼합비는 4.62 : 1 (체적비)로 나타났다. 두 가지 섬유로 보강한 무근콘크리트보의 휨 실험에서 탄소섬유 :유리섬유 = 6.8 : 1 이상인 경우 유사연성거동이 나타남을 확인하였다. 체적비 8.8 : 1의 유리섬유-탄소섬유 하이브리드 시트를 제작하고, 철근콘크리트보를 보강한 후 휨 실험을 수행하였다. 하이브리드 시트 1겹 및 2겹으로 보강한 보에서 모두 무보강 보에 비하여 강도가 증진하는 반면에, 연성이 유지되는 결과를 확인하였다. 하이브리드 시트를 사용하면 탄소섬유를 사용한 보강에 비하여 보다 경제적이면서 탄소섬유와 동등 이상의 강도 및 보다 우수한 연성을 나타내었다. 하이브리드 시트를 사용한 휨 부재 보강에서 한 가지 섬유만을 사용하는 기존의 설계 방법을 적용하여도 보수적인 설계가 가능하였다.

고인성 외곽 거푸집의 역학성능 및 이를 활용한 고강도 RC기둥의 내화성능에 관한 실험적 연구 (An Experimental Study on the Mechanical Properties of Ductile Outline Form and Fire Resistance of High Strength RC Column)

  • 노형남;김재환;김용로;김욱종;권영진;이상수
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2008년도 추계 학술논문 발표대회
    • /
    • pp.199-203
    • /
    • 2008
  • With recent trend in domestic and global market requiring architectures' conversion into skyscrapers seasoned with the features of landmarks, structural problems in relation with explosive spatting during fire emergencies are arising as controversial issues. Accordingly, many productive researches have been made in relation to the reinforcement techniques for improving fire resistance and the number of applications in the field is gradually increasing. In this study, a ductile outline form using ECC (Engineered Cementations Composites) was made with improvements on the structure and fire resistance to examine its applicability. Also, currently in Japan, the number of studies and applications is increasing focusing on reduction of construction time and improvement of workability with application of Half-PCa method. However, using such method of construction, large structural members decrease the utilization of space and architecture-wise, there is a disadvantage of the weight increase. Therefore, in such context, it would be worth reducing the weight of the structural members by reducing the size using ECC. In addition, its excellent pseudo strain-hardening due to fiber may have great effects on seismic designs. In the mean time, this study planned 3 equal conditions for mix water, PVA fiber and additives excluding binder and refractory to evaluate the mechanical properties of resistance against pressure and internal force. Finally, an evaluation was executed on the fire resistance of the newly made ductile outline form. As a result, from ECC-I to ECC-III, all showed excellent mechanical properties due to pseudo strain-hardening and in the fire resistance test conducted with ISO 834 heating curve, most of them tended to be in the range of the reference temperature (538℃-180min), so there was no occurrence of any explosive spatting.

  • PDF

강합성교각의 내진성능평가 Part II: 유사동적실험 및 잔류내진성능 평가 (Seismic Performance of Concrete-Filled Steel Piers Part II: Pseudo-Dynamic Test and Residual Seismic Capacity)

  • 조창빈;서진환;장승필
    • 한국지진공학회논문집
    • /
    • 제6권2호
    • /
    • pp.21-28
    • /
    • 2002
  • Ductile behavior and strength of concrete-filled steel(CFS) piers was supported by many quasi-static cyclic loading tests. This test method, however, only estimates the member′s deformation capacity under escalating and repetitive displacement and ignores dynamic and random aspects of an earthquake load. Therefore, to understand complete seismic behavior of the structure against an earthquake, dynamic tests such as shaking table test and pseudo-dynamic tests are required as well as quasi-static tests. In this paper, following "Seismic Performance of Concrete-Filled Steel Piers Part I : Quasi-Static Cyclic Loadint Test", the seismic behavior of CFS and steel piers designed for I-Soo overpass in Seoul in investigated by the pseudo-dynamic test. In addition, the residual strength of both piers after an earthquake is estimated by the quasi-static test. The results show that both piers have satisfactory ductility and strength against well-known EI Centro earthquake although the CFS pier has better strength and energy dissipation than the steel pier.

마이크로 역학과 레올로지 제어에 의한 고인성 섬유복합재료 ECC(Engineered Cementitious Composite)의 다양한 타설 공정 구현 (Facilitation of the Diverse Processing of High Ductile ECC (Engineered Cementitious Composite) Based on Micromechanics and Rheological Control)

  • 김윤용;김정수
    • 한국농공학회논문집
    • /
    • 제47권5호
    • /
    • pp.27-39
    • /
    • 2005
  • In the recent design of high ductile fiber-reinforced ECC (engineered cementitious composite), optimizing both processing and mechanical properties for specific applications is critical. This study presents an innovative method to develop new class ECCs, which possess the different fluid properties to facilitate diverse types of processing (i.e., self-consolidating or shotcrete processing) while maintaining ductile hardened properties. In the material design concept, we employ a parallel control of fresh and hardened properties by using micromechanics and cement rheology. Control of colloidal interaction between the particles is regarded as a key factor to allow the performance of the specific processing. To determine how to control the particle interactions and the viscosity of cement suspension, we first introduce two chemical admixtures including a highly charged polyelectrolyte and a non-ionic polymer. Optimized mixing steps and dosages we, then, obtained within the solid concentration predetermined based on micromechanical principle. Test results indicate that the rheological properties altered by this approach were revealed to be highly effective in obtaining the desired function of the fresh ECC, allowing us to readily achieve hardened properties, represented by pseudo strain-hardening behavior in uniaxial tension.

콘크리트 구조물용 하이브리드 섬유강화 복합재료 리바 물성에 관한 실험적연구 (An Experimental Study on the Mechanical Properties of Hybrid Fiber Reinforced Plastic(FRP) Rebar for Concrete Structure)

  • 배시연;신용욱;한길영;이동기;심재기
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 2000년도 춘계학술발표대회 논문집
    • /
    • pp.63-66
    • /
    • 2000
  • This paper describes the need for a ductile Fiber Reinforced Plastic(FRP) reinforcement for concrete structures. Using the material hybrid and geometric hybrid, it is demonstrated that the pseudo-ductility characteristic can be generated in FRP rebar. Ductile hybrid FRP bars were successfully fabricated at 4mm and l0mm nominal diameters using an hand lay up method. Tensile specimens from these bars were tested and compared with behavior of FRP rebar and steel bar

  • PDF

브레이드 투루젼법에 의한 콘크리트 구조물용 케블라-유리섬유 강화 복합재료 리바 특성 (Characteristics of Kevlar-Glass fiber reinforced plastic for Concrete Structure by the Braidtrusion process)

  • 최명선;곽상묵;배시연;이동기;심재기;한길영
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 2002년도 춘계학술발표대회 논문집
    • /
    • pp.48-52
    • /
    • 2002
  • This paper describes the need for a ductile Fiber Reinforced Plastic(FRP) reinforcement for Concrete Structures. Using the material hybrid and geometric hybrid, it is demonstrated that the pseudo-ductility Characteristic can be generated in FRP rebar. Ductile hybrid FRP bars were successfully fabricated at Ø3mm and Ø10mm nominal diameters using the braidtrusion process. Tensile and bending specimens from these bars were tested and compared with behavior of stress-strain of steel bar and GFRP rebar

  • PDF

역량스펙트럼 및 에너지분석을 이용한 RC교각의 내진성능평가에 관한 연구 (Seismic Performance Evaluation of RC Bridge Piers using Capacity Spectrum and Energy Analysis)

  • 정영수;박종협
    • 한국지진공학회:학술대회논문집
    • /
    • 한국지진공학회 2001년도 춘계학술대회 논문집
    • /
    • pp.361-367
    • /
    • 2001
  • This research aims at evaluating the seismic performance of the R/C bridge piers, which were seismically designed in accordance with the seismic provision of limited ductile behavior of Eurocode 8. Pseudo dynamic test for six(6) circular RC bridge piers has been carried out so at to investigate their seismic performance subjected to experted artificial earthquake motions. The objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete bridge piers. Important test parameters are confinement steel ratio, input ground motion, etc. The seismic behavior of circular concrete piers under artificial ground motions has been evaluated through displacement ductility, energy analysis, capacity spectrum. It can be concluded that RC bridge piers designed in the seismic code of limited ductile behavior of Eurocode 8 have been determined to show good seismic performance even under expected artificial earthquakes in moderate seismicity region.

  • PDF

라인 브레이딩 펄트루젼을 이용한 하이브리드 섬유강화 복합재료 리바 제작에 관한 연구 (A Study on the Manufacturing of Hybrid Fiber Reinforced Plastic Rebar Using In-Line Braiding and Pultrusion)

  • 신용욱;한길영;이동기;심재기;오환교
    • 한국해양공학회:학술대회논문집
    • /
    • 한국해양공학회 2000년도 춘계학술대회 논문집
    • /
    • pp.57-62
    • /
    • 2000
  • This paper describes the need for a ductile Fiber Reinforced Plastic(FRP) reinforcement for concrete structures. Using the material hybrid and geometric hybrid. it is demonstrated that the pseudo-ductility characteristic can be generated in FRP rebar. Ductile hybrid FRP bars were successfully fabricated at 4mm and 10mm nominal diameters using an hand lay up method. Tensile specimens from these bars were tested and compared with behavior of FRP rebar and steel bar

  • PDF