• 제목/요약/키워드: rigidity capacity

검색결과 113건 처리시간 0.028초

Structural Behavior of Beam-Column Joints Consisting of Composite Structures

  • Lee, Seung-Jo;Park, Jung-Min;Kim, Wha-Jung
    • KCI Concrete Journal
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    • 제14권3호
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    • pp.111-120
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    • 2002
  • This study proposes a joint model consisting of different types of members as a new structural system, and then investigates the resulting structural behavior. The joint model consists of a concrete-filled steel tube column (CFT) together with a steel reinforced concrete at the end plus reinforced concrete beam at the center. For comparison, two other joint models were designed, that are, a CPT with a reinforced concrete beam, and a CFT with a steel reinforced concrete at the end plus steel concrete beam at the center, then their joint capacity and rigidity, energy absorption capacity, etc., were all investigated. From the results, the CFT column with a steel reinforced concrete at the end plus steel concrete beam at the center was outstanding in terms of its capacity and rigidity. The results of this analysis demonstrate that an adequate connection type and reinforcement method with different materials of increasing the rigidity, thereby producing a capacity improvement along with protection from pre-fractures.

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Investigation on mechanical performance of flat steel plate-lightweight aggregate concrete hollow composite slab

  • Yang, Yong;Chen, Yang;Yang, Ye;Zeng, Susheng
    • Steel and Composite Structures
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    • 제31권4호
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    • pp.329-340
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    • 2019
  • An innovated type of the flat steel plate-lightweight aggregate concrete hollow composite slab was presented in this paper. This kind of the slab is composed of flat steel plate and the lightweight aggregate concrete slab, which were interfaced with a set of perfobond shear connectors (PBL shear connectors) with circular hollow structural sections (CHSS) and the shear stud connectors. Five specimens were tested under static monotonic loading. In the test, the influence of shear span/height ratios and arrangements of CHSS on bending capacity and flexural rigidity of the composite slabs were investigated. Based on the test results, the crack patterns, failure modes, the bending moment-curvature curves as well as the strains of the flat steel plate and the concrete were focused and analyzed. The test results showed that the flat steel plate was fully connected to the lightweight aggregate concrete slab and no obvious slippage was observed between the steel plate and the concrete, and the composite slabs performed well in terms of bending capacity, flexural rigidity and ductility. It was further shown that all of the specimens failed in bending failure mode regardless of the shear span/height ratios and the arrangement of CHSS. Moreover, the plane-section assumption was proved to be valid, and the calculated formulas for predicting the bending capacity and the flexural rigidity of the composite slabs were proposed on the basis of the experimental results.

Seismic behaviour of steel beam-to-column joints with column web stiffening

  • Ciutina, A.L.;Dubina, D.
    • Steel and Composite Structures
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    • 제6권6호
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    • pp.493-512
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    • 2006
  • The present paper summarizes the experimental research carried out at the "Politehnica" University of Timisoara, Romania, with the scope of investigating the influence of different column web stiffening solutions on the performance of beam-to-column joints of Moment Resisting Steel Frames. The response parameters, such as resistance, rigidity and ductility were examined. Five different types of panel web stiffening were compared with regard to a reference test. A quasi-linear relationship between the moment capacity and the total shear area of the web panel was observed from the experimental tests while the initial rigidity increased non-proportionally with the same area. Comparisons are presented of the experimental tests with the mathematical model developed by Krawinkler and with the model stipulated in Eurocode 3 Part 1.8. These comparisons showed a generally good agreement in the case of moment capacity, while the computed rigidities were always greater than the experimental rigidities.

AN EVALUATION ON THE EFFECTIVE FLEXURAL RIGIDITY OF RC SLABS STRENGTHENED WITH CFRP SHEET AND GSP PLATE

  • Shim Jae-Joong;Song Seul-Ki;Oh Min-Ho;Cui-Jie;Park Sun-Kyu
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1272-1277
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    • 2009
  • Since improved capacity for RC bridges has been required due to deterioration or increase in traffic, the deflection of cracked reinforced concrete slabs need to be reconsidered. Strengthening is known as the better way to improve capacity of bridges than reconstructing. In this paper, Fiber Reinforced Plastic (FRP) was introduced as one of the best strengthening methods for civil structures. The structures strengthened with FRPs can improve the strengthening capacity and serviceability. Therefore, CFRP sheet and Glass Fiber-Steel Composite Plate (GSP) in this research were used for strengthening slabs of RC bridges. Experimental data from the strengthening will be helpful to better understand the effect of the strengthening and effective flexural rigidity.

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혼합구조로 이루어진 보-기둥 접합부의 구조적 거동 특성 (The Properties for Structural Behavior of Beam-Column Joint Consisting of Composite Structure)

  • 이승조;박정민;김화중
    • 한국강구조학회 논문집
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    • 제12권4호통권47호
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    • pp.445-455
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    • 2000
  • 본 연구는 최근의 건설 환경 변화에 따른 여러 가지 제문제점들에 대한 구조적 측면에서의 대응책의 하나로서 새로운 구조 시스템 전개를 위해 이종구조부재로 구성된 보기둥 접합부 모델을 제안한 것이다. 본 연구에서는 장스팬 S보의 강성을 향상시키기 위해 S조의 단부를 RC조로 보강하여 강성 및 내력증대를 꾀하였으며, 이종구조 사이의 원활한 응력 전달을 목적으로 SRC조 단부의 보 주근은 U자형 갈고리 모양으로 정착하여 철골 플랜지에 용접 접합하였다. 일련의 실험을 통해 접합부 강성 및 내력 특성을 고찰하였고 본 접합부의 가능성을 제시하였다.

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연직 마이크로파일이 설치된 조밀한 모레지반의 지지력 증가에 관한 연구 (A Study on Increase of Bearing Capacity of Dense Sandy Ground installed by Vertical Micropiles)

  • 최상민;임종철;이태형;공영주
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.355-362
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    • 2001
  • Since micropiles were conceived in Italy in the early 1950s, which have been widely used for In-situ reinforcement, bearing pile or the concept of combination in the world-wide. The meaning of micropiles usually differs from that of a general deep foundation. Because the load capacity of it was mainly affected by skin friction. Also, it could be obtained the improvement effects of load capacity or ground's rigidity by the unitary behavior of ground and micropiles. In this study, The model tests were peformed on the dense sand where micropiles are set to the vertical direction. Strip footing was used in it. Steel bars of dia. 2 and 4㎜ were used in model tests of which the sand was attached on the surface, and the length of it was changed as 2B to 6B(where, B is width of strip footing) Through this process, the load capacity were analyzed from the test results in the relationship between load and displacement.

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한국형 저상버스 복합소재 차체에 대한 비틀림 강성 평가 (Torsion Rigidity of Composite Material Cmbody for Low Floor Bus)

  • 임송규;김연수;목재균;장세기;조세현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.548-553
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    • 2008
  • Low Floor buses have no steps to get on or get off the main cabin to provide the old and the handicapped with easy access. The car body for the low floor bus was designed to consider Korean physical standard, passenger capacity (standee, seated, handicapped), arrangement of vehicle components, and bus law or regulations. It was designed as an one body, without any reinforcement armature, which has light-weight sandwich constructions with glass epoxy skins, aluminum honeycomb cores and inner-frames. In this paper, torsion rigidity of the designed car body was evaluated and compared with that of a car body with reinforcement armatures in the cabin. Finite element method verified that the designed car body without reinforcement armatures could satisfy requirements of torsion rigidity.

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Experimental and theoretical research on mechanical behavior of innovative composite beams

  • Zhu, Gang;Yang, Yong;Xue, Jianyang;Nie, Jianguo
    • Steel and Composite Structures
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    • 제14권4호
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    • pp.313-333
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    • 2013
  • The web-encased steel-concrete composite (WESCC) beam is a new developed steel-concrete composite beam. Experiments of six simply supported WESCC beam specimens were conducted. The effects of the shear-span ratio and steel section type were all investigated on the static behaviors such as failure modes, failure mechanism and bearing capacity. The experimental results denoted that all specimens failed in bending mode and the degree of combination between the bottom armor plate of steel shape and concrete were very well without any evident slippage, which demonstrated that the function of bottom armor plate and web were fully exerted in the WESCC beams. It could be concluded the WESCC beams have high stiffness, high load carrying capacity and advanced ductility. The design methods are proposed which mainly consist the bearing capacity calculation of bending and flexural rigidity. The calculation results of the bearing capacity and deflection which take the shear deflection into account are in agreement with the experimental results. The design methods are useful for design and application of the innovative composite beams.

Flexural performance of fire damaged and rehabilitated two span reinforced concrete slabs and beams

  • Yu, Jiang-Tao;Liu, Yuan;Lu, Zhou-Dao;Xiang, Kai
    • Structural Engineering and Mechanics
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    • 제42권6호
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    • pp.799-813
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    • 2012
  • Five two-span reinforced concrete (RC) slabs and seven two-span RC beams were tested under the ISO 834 standard fire with different durations. CFRP strengthening was then applied to some of the specimens after the damaged concrete was removed from the specimens and replaced with polymer mortar. All the specimens were loaded to failure to investigate the influence of fire-damage and the effectiveness of strengthening methods. Test results indicated that the flexural capacities of specimens decrease with the fire duration increases. Moreover, fire exposure had more significant effect on the flexural rigidity than on the bearing capacity of the specimens. After rehabilitation, the bearing capacities of specimens reached or even exceeded that of the reference RC specimen, and the strengthening methods seemed to have limited effect on flexural rigidity recovery. From the analysis of moment redistribution of tested beams, elevated temperature is found having different impacts on sagging moment region and hogging moment region. The damage of RC continuous member is definitely a comprehensive response of different regions.

Timber-FRP composite beam subjected to negative bending

  • Subhani, Mahbube;Globa, Anastasia;Moloney, Jules
    • Structural Engineering and Mechanics
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    • 제73권3호
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    • pp.353-365
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    • 2020
  • In the previous studies, the authors proposed the use of laminated veneer lumber - carbon fiber reinforced polymer (LVL-CFRP) composite beams for structural application. Bond strength of the LVL-to-CFRP interface and flexural strengthening schemes to increase the bending capacity subjected to positive and negative moment were discussed in the previous works. In this article, theoretical models are proposed to predict the moment capacity when the LVL-CFRP beams are subjected to negative moment. Two common failure modes - CFRP fracture and debonding of CFRP are considered. The non-linear model proposed for positive moment is modified for negative moment to determine the section moment capacity. For the debonding based failure, previously developed bond strength model for CFRP-to-LVL interface is implemented. The theoretical models are validated against the experimental results and then use to determine the moment-rotation behaviour and rotational rigidity to compare the efficacy of various strengthening techniques. It is found that combined use of bi- and uni-directional CFRP U-wrap at the joint performs well in terms of both moment capacity and rotational rigidity.