• Structural Engineering and Mechanics
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• 제88권1호
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• pp.53-65
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• 2023

With the gradual implementation of long-span suspension bridges into high-speed railway operations, the main beam's bending stiffness contribution to the live load response permanently grows. Since another critical control parameter of railway suspension bridges is the beam-end rotation angle, it should not be ignored by treating the main beam deflection as the only deformation response. To this end, the current study refines the existing method of the main cable shape and simply supported beam bending moment analogy. The bending stiffness of the main beam is considered, and the main beam's analytical expressions of deflection and rotation angle in the whole span are obtained using the cable-beam deformation coordination relationship. Taking a railway suspension bridge as an example, the effectiveness and accuracy of the proposed analytical method are verified by the finite element method (FEM). Comparison of the results by FEM and the analytical method ignoring the main beam stiffness revealed that the bending stiffness of the main beam strongly contributed to the live load response. Under the same live load, as the main beam stiffness increases, the overall deformation of the structure decreases, and the reduction is particularly noticeable at locations with original larger deformations. When the main beam stiffness is increased to a certain extent, the stiffening effect is no longer pronounced.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.398-401
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• 2006

This study investigates the behaviour of Hybrid Beam with reinforced concrete encased steel center and reinforced concrete end. Two types of encased steel shape and two sections are examined in this study. Test results showed that H-Hybrid beam is stronger than Honey-comb Hybrid beam, and the behaviour of composite beam embedded steel at the elastic state is same as that of simple beam.

• Steel and Composite Structures
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• 제9권2호
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• pp.159-172
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• 2009

Two prestressed steel reinforced high performance concrete (SRC) beams, a nonprestressed SRC beam and a counterpart prestressed concrete beam were tested under low reversed cyclic loading to evaluate seismic performance of prestressed SRC beams. The failure modes, deformation restoring capacity, ductility and energy dissipation capacity of the prestressed SRC beams were discussed. Results showed that due to the effect of plastic deformations of steel beams encased in concrete, the three SRC beams exhibited residual deformation ratios ranging between 0.64 and 0.79, which were apparently higher than that of the prestressed concrete beam (0.33). The ductility coefficients of the prestressed SRC beams and the prestressed concrete beam ranged between 4.65 and 4.87, obviously lower than that of nonprestressed SRC beam (9.09), which indicated the steel beams influenced the ductility little while prestressing resulted in an apparent reduction in ductility. The amount of energy dissipated by the prestressed SRC beams was less than that dissipated by the nonprestressed SRC beam but much more than that dissipated by the prestressed concrete beam.

• Architectural research
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• 제1권1호
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• pp.55-61
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• 1999

In reinforced concrete design, structural member sizes and amount of reinforcing steel areas are usually selected based on the structural designers' experience. Most existing charts provided for the design of reinforced concrete structural members were developed mainly based on force equilibrium conditions and some serviceability criteria. Sections selected from these charts may not result in an economic solution in terms of material costs as well as construction costs. Practical design aids are developed and suggested in this study for the economical design of reinforced concrete beam under flexural loading. With the beam width fixed, the depth of a beam, positive steel areas and negative steel areas are found from Khun-Tucker necessary conditions with Lagrangian multipliers to minimize the sectional cost of a beam. The developed design aids might be useful in selecting optimum reinforced concrete beam sections. Theoretical derivations and use of the developed design aids are described in this paper.

• 콘크리트학회논문집
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• 제12권2호
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• pp.53-62
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• 2000

Under severe lateral loads, ductile moments-resisting reinforced concrete frames will be subjected to large loads and displacements. Thus, large deformation and shear stree are occurred at the beam-column joints which are the most critical region in ductile moments-resisting system. The purpose of this study was to investigate the shear strength of beam-column connection using high strength concrete. Four subassemblies were designed 2/3 scale of read structures and tested. The obtained results are as follows. 1) The transverse beams increase the shear resistance and ductility of joint, 2) The slab was contributed to increase of the flexural capacity of the beam, but was not contributed to increase the joint ductility under cyclic loads. 3) The shear stress factors. given by the ACI code would be modified in evaluating the shear strength of beam-column joints of frame which were constructed with high-strength concrete.

• 교육녹색환경연구
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• 제10권2호
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• pp.1-7
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• 2011

An experimental study to evaluate structural capacity of an embedded plate connected with prestressed concrete beam was performed. Embedded steel plates and prestressed concrete beam were connected with stud-bolts at the ends of concrete beam specimens. About 1,000 kN concentrated load was applied at 450mm away from the end of beam specimen. A 3,000 kN capacity static Oil-jack was used to direct concentrated load. The maximum strain of stud-bolt recorded $90{\times}10^{-6}$(mm/mm) and wide width cracks were not founded. Any falling failures of concrete and large deformations were not founded either between steel plate and prestressed concrete specimen. As a result, construction performance can be improved using this embedded steel plate connection system apply to large space educational facilities.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.19-20
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• 2013

Green Frame is a column-beam system constructed by composite precast column and beam connected by embedded steel of their. From when the precast concrete beam of Green Frame is installed, until the concrete of slab and connection joint is cured, the self load of beam shall be supported by the embedded steel of it. Therefore, the concrete of beam could be separated from the embedded steel if the shear connector of beam of Green Frame is designed by the code on Structural standard. So, this study suggest an equation for the shear connection of composite precast concrete beams of Green Frame. The result of this study will be used as the main equation of the calculation model for shear connectors of composite precast concrete beams.

• 한국구조물진단유지관리공학회 논문집
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• 제2권4호
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• pp.159-171
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• 1998

This study attempts to develop a rational approach to flexural concrete beam analysis with crack growth. In order to develope analytical solutions, several simplification and assumption are made and the Hillerborg fictitious crack model is adapted for new rational approach to the flexural concrete beam. To provide desired results, the concrete beams with various conditions(more than 126 beam conditions) are analyzed. Before producing the results, these assumptions are founded to be justified by comparison with a FE analysis. The results for each condition of the beams are presented in terms of crack lengths, the strength and cracking stability of concrete beams. And also size effects in a flexural concrete beam is studied using a new flexural cracking model.

• Steel and Composite Structures
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• 제49권3호
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• pp.349-359
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• 2023

Dynamic response and economic of a laminated porous concrete beam reinforced by nanoparticles subjected to harmonic transverse dynamic load is investigated considering structural damping. The effective nanocomposite properties are evaluated on the basis of Mori-Tanaka model. The concrete beam is modeled by the sinusoidal shear deformation theory (SSDT). Utilizing nonlinear strains-deflection, energy relations and Hamilton's principal, the governing final equations of the concrete laminated beam are calculated. Utilizing differential quadrature method (DQM) as well as Newmark method, the dynamic displacement of the concrete laminated beam is discussed. The influences of porosity parameter, nanoparticles volume percent, agglomeration of nanoparticles, boundary condition, geometrical parameters of the concrete beam and harmonic transverse dynamic load are studied on the dynamic displacement of the laminated structure. Results indicated that enhancing the nanoparticles volume percent leads to decrease in the dynamic displacement about 63%. In addition, with considering porosity of the concrete, the dynamic displacement enhances about 2.8 time.