• Title/Summary/Keyword: Beam action

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Ultimate strength of composite structure with different degrees of shear connection

  • Kim, Sang-Hyo;Jung, Chi-Young;Ahn, Jin-Hee
    • Steel and Composite Structures
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    • v.11 no.5
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    • pp.375-390
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    • 2011
  • Composite beam, which combined the material characteristic of the steel and concrete, has been widely used in the construction of various building and bridge system. For the effective application of the composite beam, the composite action on the composite interface between the concrete element and the steel element should be achieved by shear connectors. The behavioral characteristics of composite beam are related with the degree of interaction and the degree of shear connection according to the shear strength and shear stiffness of the stud shear connectors. These two concepts are also affected by the number of installed shear connector and the strength of composite materials. In this study, experimental and analytical evaluations of the degree of shear connection affected by stud diameter were conducted, and the relationship between structural behavior and the degree of shear connection was verified. The very small difference among the ultimate loads of the specimens depending on the change of the degree of connection was possibly because of the dependence of the ultimate load on the characteristic of plastic moment of the composite beam.

Research on anti-seismic property of new end plate bolt connections - Wave web girder-column joint

  • Jiang, Haotian;Li, Qingning;Yan, Lei;Han, Chun;Lu, Wei;Jiang, Weishan
    • Steel and Composite Structures
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    • v.22 no.1
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    • pp.45-61
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    • 2016
  • The domestic and foreign scholars conducted many studies on mechanical properties of wave web steel beam and high-strength spiral stirrups confined concrete columns. Based on the previous research work, studies were conducted on the anti-seismic property of the end plate bolt connected wave web steel beam and high-strength spiral stirrups confined concrete column nodes applied with pre-tightening force. Four full-size node test models in two groups were designed for low-cycle repeated loading quasi-static test. Through observation of the stress, distortion, failure process and failure mode of node models, analysis was made on its load-carrying capacity, deformation performance and energy dissipation capacity, and the reliability of the new node was verified. The results showed that: under action of the beam-end stiffener, the plastic hinges on the end of wave web steel beam are displaced outward and played its role of energy dissipation capacity. The study results provided reliable theoretical basis for the engineering application of the new types of nodes.

Design and Analysis of a State Feedback Controller for a Ball and Beam System under AC and DC Noise (볼-빔 시스템에서 AC 와 DC 노이즈가 포함된 상태 궤환 제어기 설계 및 분석)

  • Oh, Sang-Young;Choi, Ho-Lim
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.6
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    • pp.641-646
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    • 2014
  • In this paper, we propose a controller for a ball and beam system which reduces the measurement error effect under AC and DC noise. The ball and beam system measures data through a sensor. If sensor noise is included in a controller via the feedback channel, the signal is distorted and the entire system cannot work normally. Therefore, some appropriate action for the measurement error effect is essential in the controller design. Our controller is equipped with a gain-scaling factor and a compensator to reduce the effect of measurement error in the feedback signal. Effectively, our proposed controller can reduce the AC and DC noise of a feedback sensor. We analyze the proposed controller by Laplace transform technique and illustrate the improved control performance via an experiment for a ball and beam system.

A study on implementation of beam forming system for LED communication using micro controller (마이크로 컨트롤러를 이용한 LED 통신의 선택적 빔 포밍 시스템 구현에 관한 연구)

  • Lee, JungHoon;Kim, Chan;Cha, Jaesang
    • Journal of Satellite, Information and Communications
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    • v.7 no.2
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    • pp.25-29
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    • 2012
  • In this paper, we implemented LED beam forming communication system controlled by stepping motor. ATMega1284 was used as a MCU of main control board which has two main external IO, one is RS232 for connection with PC, the other is PORT for connection with motor driving board. Stepping motor rotated 360 degree when provided 160 clock and its rotation radius was increased by Archimedian Spiral. So LED can provide its light anywhere in the space and its beam forming was controlled by PC connected with RS232 of main control board. The action of beam forming was verified via actual HW/SW implementation.

Behavior of composite CFST beam-steel column joints

  • Eom, Soon-Sub;Vu, Quang-Viet;Choi, Ji-Hun;Papazafeiropoulos, George;Kim, Seung-Eock
    • Steel and Composite Structures
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    • v.32 no.5
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    • pp.583-594
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    • 2019
  • In recent years, composite concrete-filled steel tubular (CFST) members have been widely utilized in framed building structures like beams, columns, and beam-columns since they have significant advantages such as reducing construction time, improving the seismic performance, and possessing high ductility, strength, and energy absorbing capacity. This paper presents a new composite joint - the composite CFST beam-column joint in which the CFST member is used as the beam. The main components of the proposed composite joint are steel H-beams, CFST beams welded with the steel H-column, and a reinforced concrete slab. The steel H-beams and CFST beams are connected with the concrete slab using shear connectors to ensure composite action between them. The structural performance of the proposed composite joint was evaluated through an experimental investigation. A three-dimensional (3D) finite element (FE) model was developed to simulate this composite joint using the ABAQUS/Explicit software, and the accuracy of the FE model was verified with the relevant experimental results. In addition, a number of parametric studies were made to examine the effects of the steel box beam thickness, concrete compressive strength, steel yield strength, and reinforcement ratio in the concrete slab on the proposed joint performance.

Cyclic behaviour of concrete encased steel (CES) column-steel beam joints with concrete slabs

  • Chu, Liusheng;Li, Danda;Ma, Xing;Zhao, Jun
    • Steel and Composite Structures
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    • v.29 no.6
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    • pp.735-748
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    • 2018
  • In this paper, the cyclic behavior of steel beam-concrete encased steel (CES) column joints was investigated experimentally and numerically. Three frame middle joint samples with varying concrete slab widths were constructed. Anti-symmetrical low-frequency cyclic load was applied at two beam ends to simulate the earthquake action. The failure modes, hysteretic behavior, ultimate load, stiffness degradation, load carrying capacity degradation, displacement ductility and strain response were investigated in details. The three composite joints exhibited excellent seismic performance in experimental tests, showing high load-carrying capacity, good ductility and superior energy dissipation ability. All three joint samples reached their ultimate loads due to shear failure. Numerical results from ABAQUS modelling agreed well with the test results. Finally, the effect of the concrete slab on ultimate load was analyzed through a parametric study on concrete strength, slab thickness, as well as slab width. Numerical simulation showed that slab width and thickness played an important role in the load-carrying capacity of such joints. As a comparison, the influence of concrete grade was not significant.

Effect of the GFRP wrapping on the shear and bending Behavior of RC beams with GFRP encasement

  • Ozkilic, Yasin Onuralp;Gemi, Lokman;Madenci, Emrah;Aksoylu, Ceyhun;Kalkan, İlker
    • Steel and Composite Structures
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    • v.45 no.2
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    • pp.193-204
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    • 2022
  • The need for establishing the contribution of pultruded FRP encasements and additional FRP wraps around these encasements to the shear strength and load-deflection behavior of reinforced concrete beams is the main motivation of the present study. This paper primarily focuses on the effect of additional wrapping around the composite beam on the flexural and shear behavior of the pultruded GFRP (Glass Fiber Reinforced Polymer) beams infilled with reinforced concrete, taking into account different types of failure according to av/H ratio (arch action, shear-tension, shear-compression and pure bending). For this purpose, nine hybrid beams with variable shear span-to-depth ratio (av/H) were tested. Hybrid beams with 500 mm, 1000 mm, and 1500 mm lengths and cross-sections of 150x100 mm and 100x100 mm were tested under three-point and four-point loading. Based on the testing load-displacement relationship, ductility ratio, energy dissipation capacity of the beams were evaluated with comprehensive macro damage analysis on pultruded GFRP profile and GFRP wrapping. The GFRP wraps were established to have a major contribution to the composite beam ductility (90-125%) and strength (40-75%) in all ranges of beam behavior (shear-dominated or dominated by the coupling of shear and flexure). The composite beams with wraps were showns to reach ductilities and strength values of their counterparts with much greater beam depth.

Connection rotation requirements on FRP-strengthened steel-concrete composite beam systems

  • Panagiotis M. Stylianidis;Michael F. Petrou
    • Structural Engineering and Mechanics
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    • v.92 no.2
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    • pp.133-147
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    • 2024
  • Composite beams of steel and concrete strengthened with fiber-reinforced polymers (FRP) may exhibit considerably enhanced flexural behaviour, but the combination of three materials with different characteristics and the various possible failure mechanisms that may govern performance make their analysis quite demanding. Previous studies provided significant insights into this problem and several methods were proposed for calculating flexural stiffness and strength, but these studies are restricted to the single member level of a simply supported composite beam section. However, the problem considerably changes when the beam is part of a frame system due to the degree of continuity provided by the surrounding structure, which represents the most common situation in practice. This paper explores the behaviour of semi-continuous FRP-strengthened composite beams, by considering the response characteristics of their end connections and their effects on overall performance. A novel analytical model is derived, which enables a step-by-step representation of the nonlinear relationship between an incremental mid-span design bending moment and corresponding connection rotations. After verification against finite element analyses, a parametric study is conducted which shows that the substantially increased bending moment resistance of FRP-strengthened composite beams can hardly be fully utilized due to a deficiency of corresponding large deformation capacity available in the connections. The extent to which the presence FRP strengthening can be exploited to enhance the beam flexural response depends on the interplay between various structural parameters, including the connection rotation capacity, the beam span, and the FRP modulus of elasticity and ultimate strength.

Reinforced concrete beam-column joints with lap splices under cyclic loading

  • Karabinis, Athanasios I.
    • Structural Engineering and Mechanics
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    • v.14 no.6
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    • pp.649-660
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    • 2002
  • Experimental results are presented from tests conducted on reinforced concrete beam-column joints with lap splices under reversed cyclic loading simulating earthquake action. Response curves are compared for twenty-four specimens designed according to Eurocode 2. The main parameters of the investigation are, the geometry of the reinforcing bar extension, the applied axial load (normalized), the available cover over lap splice region extended as length required from Eurocode 2, as well as the shape and the volumetric percentage of the stirrups confining the lap splice zone. The results are evaluated with regards to the load intensity, the energy absorption capacity and the characteristics of the load deflection curve.

An Experiment Study of Cyclic Seismic Behavior of Steel Moment Connections Reinforced with Ribs (리브로 보강된 철골 모멘트 접합부의 내전거동에 관한 실험적 연구)

  • 이철호;이재광;정종현;오명호;구은숙
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.317-326
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    • 2002
  • Recently a simple design method for rib-reinforced seismic steel moment connections has been proposed based on equivalent strut model. An experimental program was implemented to verify the proposed design method and to develop the schemes that will prevent the cracking at the rib tip, where stress concentration was evident. All the specimens designed by the proposed method were able to develop satisfactory connection plastic rotation of 0.04 radian. Slight beam flange trimming, in addition to rib reinforcement, pushed the plastic hinging and local buckling of the beam away from the rip tip and effectively reduced the cracking potential at the rib tip. The strut action of the rib and resulting reverse shear in the beam web were also experimentally identified through the strain gage readings.

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