• Title/Summary/Keyword: test beam

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Experimental Cyclic Behavior of Precast Hybrid Beam-Column Connections with Welded Components

  • Girgin, Sadik Can;Misir, Ibrahim Serkan;Kahraman, Serap
    • International Journal of Concrete Structures and Materials
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    • v.11 no.2
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    • pp.229-245
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    • 2017
  • Post-earthquake observations revealed that seismic performance of beam-column connections in precast concrete structures affect the overall response extensively. Seismic design of precast reinforced concrete structures requires improved beam-column connections to transfer reversed load effects between structural elements. In Turkey, hybrid beam-column connections with welded components have been applied extensively in precast concrete industry for decades. Beam bottom longitudinal rebars are welded to beam end plates while top longitudinal rebars are placed to designated gaps in joint panels before casting of topping concrete in this type of connections. The paper presents the major findings of an experimental test programme including one monolithic and five precast hybrid half scale specimens representing interior beam-column connections of a moment frame of high ductility level. The required welding area between beam bottom longitudinal rebars and beam-end plates were calculated based on welding coefficients considered as a test parameter. It is observed that the maximum strain developed in the beam bottom flexural reinforcement plays an important role in the overall behavior of the connections. Two additional specimens which include unbonded lengths on the longitudinal rebars to reduce that strain demands were also tested. Strength, stiffness and energy dissipation characteristics of test specimens were investigated with respect to test variables. Seismic performances of test specimens were evaluated by obtaining damage indices.

Fatigue Behavior of Reinforced Dual Concrete Beam (철근 이중 콘크리트 보의 피로 거동)

  • Park, Tae-Hyo;Lee, Sang-Hee
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.37-40
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    • 2005
  • Reinforced dual concrete beam (RDC beam) is the reformed system that improves the overall structural properties of beam by partially applying high performance steel fiber reinforced concrete (HPSFRC) in the lower tension part of conventional reinforced concrete beam (RC beam). Fatigue test was done to prove the structural superiority of RDC beam. As a result of fatigue test, the deflection of RDC beam was decreased obviously and the slope of number of cycle-deflection relation curve of RDC beam was increased gently in comparison with RC beam.

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Structural Behavior of Reinforced Concrete column and Steel beam Joints (철근 콘크리트 기둥과 철골보의 합성구조 접합부 성능에 관한 연구)

  • 이원규;신동대;송진규;정혜교;최완철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.575-578
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    • 1999
  • The main objective of this study was to examine structural behavior of reinforced concrete column and steel beam joint. composite specimens about 3/4 of the actual beam column connection assembly were tested by applying cyclic load through actuators. Test variables include face bearing plate(FBP), extended face bearing plate(E-FBP), VIR, U-bar and sub beam. There is not much differenced between specimens with sub beam and without sub beam. Test results also show that the joint strength of test specimen is close to the predicted strength by ASCE guideline.

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A Study on the Bending and Seismic Performance of High Performance Cold Forming Composite Beam

  • Choi, Young Han;Kim, Sung Bae;Hong, Hyung Ju;Kim, Sang Seup
    • International journal of steel structures
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    • v.18 no.5
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    • pp.1772-1783
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    • 2018
  • Nowadays, the researches about composite structure system are being implemented in various fields, and many steel structures are designed based on that. In this study, the bending and seismic performance of the newly developed high-performance cold forming composite beam are evaluated by several experiments. As a result of the bending performance test, the bending moment of beam was increased stably depending on the depth and plate thickness of beam, and it is considered that the bending moment can be evaluated by the equation of a composite beam design. As a result of the seismic performance test, it was verified that sufficient seismic performance was obtained despite the increase of a negative moment rebar and depth of beam. In addition, the nominal bending moment has obtained the strength above the plastic bending moment, and also the plastic rotation angle has satisfied the requirement of composite intermediate moment frame.

The Bearing Strength of Connections Between Steel Coupling Beam and Reinforced Concrete Shear Walls

  • Yun, Hyun Do;Park, Wan Shin;Han, Min Ki;Kim, Sun Woo;Kim, Yong Chul;Hwang, Sun Kyung
    • Architectural research
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    • v.7 no.1
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    • pp.27-38
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    • 2005
  • No specific guidelines are available for computing the bearing strength of connection between steel coupling beam and reinforced concrete shear wall in a hybrid wall system. There were carried out analytical and experimental studies on connection between steel coupling beam and concrete shear wall in a hybrid wall system. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i.e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The proposed equations in this study were in good agreement with both our test results and other test data from the literature.

Design Study for Pulsed Proton Beam Generation

  • Kim, Han-Sung;Kwon, Hyeok-Jung;Seol, Kyung-Tae;Cho, Yong-Sub
    • Nuclear Engineering and Technology
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    • v.48 no.1
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    • pp.189-199
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    • 2016
  • Fast neutrons with a broad energy spectrum, with which it is possible to evaluate nuclear data for various research fields such as medical applications and the development of fusion reactors, can be generated by irradiating proton beams on target materials such as beryllium. To generate short-pulse proton beam, we adopted a deflector and slit system. In a simple deflector with slit system, most of the proton beam is blocked by the slit, especially when the beam pulse width is short. Therefore, the available beam current is very low, which results in low neutron flux. In this study, we proposed beam modulation using a buncher cavity to increase the available beam current. The ideal field pattern for the buncher cavity is sawtooth. To make the field pattern similar to a sawtooth waveform, a multiharmonic buncher was adopted. The design process for the multiharmonic buncher includes a beam dynamics calculation and three-dimensional electromagnetic simulation. In addition to the system design for pulsed proton generation, a test bench with a microwave ion source is under preparation to test the performance of the system. The design study results concerning the pulsed proton beam generation and the test bench preparation with some preliminary test results are presented in this paper.

A Study of Corrosion Resistance Improvement for Cr-Mo Steel in Long Term Service (장기간 사용한 Cr-Mo강의 내식성 향상 방법에 관한 연구)

  • Jin, Yeung-Jun
    • Journal of the Korean Society of Safety
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    • v.21 no.3 s.75
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    • pp.8-15
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    • 2006
  • It is no wonder that mechanical structures are accompanied by problems related to corrosion after being exposed to long hours of work. Corrosion of mechanical structures has been the most serious problem in the field of industry. The present study employed a laser beam irradiation test to improve the corrosion resistance of degraded Cr-Mo steel, which was used for more than 60,000 hours. To find the optimum irradiation test condition for the corrosion resistance of degraded Cr-Mo steel, hardness and residual stress measurements, micro-structural observation, and the electrochemical potentiokinetic reactivation (EPR) tests were performed with changes in laser beam test conditions including laser beam output, diameter, and velocity. Thus, the present study indicates that the optimum test condition and absorption energy for a laser beam test need to be determined to enhance corrosion resistance of degraded Cr-Mo steel.

Experimental Verification of Flexible Multibody Dynamic Simulations for A Rotating Beam (회전 외팔보에 대한 유연 다물체 동역학 시뮬레이션의 실험적 검증)

  • Kim, Seong-Su;Gang, Yeon-Jun;Lee, Gyu-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.267-274
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    • 2002
  • Using a flexible rotating beam test bed, experimental verification of a flexible multibody dynamic simulations for a rotating beam model has been carried out. The test bed consists of a flexible arm, harmonic driver reducer, AC servo motor and DSP board with PC. The mechanical ports of the test bed has been designed using 3D CAD program. For the simulation model, mass and moment of inertia of each part of the flexible rotating beam test bed are also obtained from 3D CAD model. In the flexible multibody dynamic simulations, the substructuring model has been established to capture nonlinear effects of the flexible rotating beam. Through the experimental verification, substructuring model provides better results than those from the linear model in the high speed rotation.

The Overall Investigation of Steel Fiber Strengthening Factor in Shear (전단에 대한 강섬유 보강계수의 종합적 고찰)

  • Lee, Hyun-Ho;Kwon, Yeong-Ho;Lee, Hwa-Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.251-254
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    • 2005
  • This study will have to define the shear strengthening effects of steel fiber in beam and column levels, as well as to suggest estimation method of maximum shear capacity of structural members. From review of literature surveys and perform structural member test results, following conclusion can be made; In beam level, steel fiber strengthening factor is suggested from the tensile splitting test results and beam test results. After suggesting shear capacity of beam without stirrups and beam with stirrups by proposed steel fiber strengthening factor, proposed equation is possible to evaluate the shear capacity of beam. In column level, with column test results and proposed steel fiber strengthening factor, shear capacity equation of steel fiber reinforced concrete in column is suggested.

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Investigation on the flexural behavior of an innovative U-shaped steel-concrete composite beam

  • Turetta, Maxime;Odenbreit, Christoph;Khelil, Abdelouahab;Martin, Pierre-Olivier
    • Steel and Composite Structures
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    • v.34 no.3
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    • pp.441-452
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    • 2020
  • Within the French CIFRE research project COMINO, an innovative type of composite beam was developed for buildings that need fire resistance with no additional supports in construction stage. The developed solution is composed of a steel U-shaped beam acting as a formwork in construction stage for a reinforced concrete part that provides the fire resistance. In the exploitation stage, the steel and the reinforced concrete are acting together as a composite beam. This paper presents the investigation made on the load bearing capacity of this new developed steel-concrete composite section. A full-scale test has been carried out at the Laboratory of Structural Engineering of the University of Luxembourg. The paper presents the configuration of the specimen, the fabrication process and the obtained test results. The beam behaved compositely and exhibited high ductility and bending resistance. The shear connection in the tension zone was effective. The beam failed by a separation between the slab and the beam at high deformations, excessive shear forces conducted to a failure of the stirrups in this zone. The test results are then compared with good agreement to analytical methods of design based on EN 1994 and design guidelines are given.