• Title/Summary/Keyword: Stiffening

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Effect of Tension Stiffering on the Behavior of Reinforced Concrete Beam (콘크리트 인장강성이 철근콘크리트 보의 거동에 미치는 영향)

  • 이봉학
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.4
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    • pp.104-112
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    • 1999
  • Tensile behavior in concrete has been neglected until recently. However, the effect of tensile stresses in concrete must be considered where the member primarily carries tensile forces or when ultimate strength is affected by the cracking history. In this paper, a series of experiments were performed with a reinforced rectangular beams of 15 specimens in order to investigate the effect of tension stiffening into the nonlinear analysis and cracking behavior. The experimental results were analyzed in terms of load-deflection curves and strain fracture energy with respect to the main experimental variables such as types of specimen, strength of concrete and steel ration. The results from experiments and finite element analysis were compared in terms of load-deflection relationship and cracking pattern. The results are as follows ; The tension stffening effects of reinforced concrete beams were observedc up to yielding of members after cracking showing strain energy difference of 35 % at the beam of 0.57% steel ratio compared with that of beam ignoring the tension stiffening effect. The tension stiffening of concrete strength 400kgf/$\textrm{cm}^2$ and 600kgf/$\textrm{cm}^2$ increased by 8% and 13%, respectively, compared with that of concrete strength 200kgf/$\textrm{cm}^2$. The tension stiffening effects were greater at a ductile member rather than a brittle one. The load-deflection results of finite element analysis showed very similar results from experiment. The crack growth and pattern might be predicted from the nonlinear finite element analysis considering concrete stiffening.

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Experimental and theoretical studies on SHS column connection with external stiffening ring under static tension load

  • Rong, Bin;You, Guangchao;Zhang, Ruoyu;Ma, Xu;Quan, Xinxin
    • Steel and Composite Structures
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    • v.28 no.2
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    • pp.167-177
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    • 2018
  • In order to investigate mechanical properties in the core area of Square Hollow Section(SHS) column connection with external stiffening ring, four specimens were tested under the static tension load. The failure modes, load-displacement curves and strain distribution were analyzed to study the mechanical properties and the load transfer mechanism of the core area of connections. The connections behave good ductility and load-bearing capacity under the static tension load. Parametric analysis was also conducted, in which the thickness of steel tube, extended width and thickness of the stiffening ring were considered as the parameters to investigate the effects on mechanical properties of the connections. Based on the experimental results, an analytical method for the bearing capacity of connection with external stiffening ring under the static tension load was proposed. The theoretical results and the experimental results are in good agreement, which indicates that the theoretical calculation method of the bearing capacity is advisable.

Tension Stiffening Effect of High Strength Concrete (고강도 콘크리트의 인장강성효과에 대한 연구)

  • Yun, Sung-Ho;Kim, Jun-Seong;Yum, Hwan-Seok;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.495-500
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    • 1998
  • This paper describes an experimental investigation on the effect of concrete strength on tension stiffening behavior. Total ten direct tension specimens were tested with concrete compressive strength range up to 900kg/$\textrm{cm}^2$. From the experimental program, it was observed that higher strength concrete specimens provides smaller crack spacings and less stiffening effect.

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The Behavior Characteristic and Buckling Strength of Stiffening-Girder of Cable stayed bridge according to Pylon's shape and Flexure Stiffness (주탑형상 및 강성이 사장교의 거동 및 주형좌굴에 미치는 영향)

  • Choe Hak-Ze;Chae Gyu-Bong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.759-763
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    • 2006
  • Cable Stayed Bridge is mainly composed of three element. Composed element are cable. stiffening girder and Pylon. The characteristic of bridge's behavior depend on these three element's relative stiffness, shape and system of bridge. The purpose of this paper is to exame the characteristic of bridge's behavior and buckling strength of stiffening girder according to shape and flexure stiffness of pylon

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Tension Stiffening Effect in Reinforced Concrete Panels (철근콘크리트 판넬의 인장강화효과)

  • 곽효경;김도연
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.141-148
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    • 1998
  • An analytical model which can simulate the post-cracking behavior of reinforced concrete structures subjected to in-plane shear and normal stresses is presented. Based on the force equilibriums, compatibility conditions, and bond stress-slip relationship between steel and concrete, a criterion to simulate consider the tension-stiffening effect is proposed. The material behavior of concrete is described by an orthotropic constitutive model, and focused on the tension-compression region with tension-stiffening and compression softening effects defining equivalent uniaxial relations in the axes of orthotropy. Correlation studies between analytical results and available experimental data are conducted with the objective to establish the validity of the proposed model.

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Buckling Stability in the deck Steel Girder of Cable stayed Bridge Considered Nonlinear Behavior of Stay Cable (케이블의 비선형 가동효과를 고려한 사장교 강거더의 좌굴 안전성 평가)

  • Choe Hak-Ze
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.129-139
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    • 2005
  • The focused topic according to be slender and longer of cable stayed bridge's main span is as follows (1) Aerodynamic stability (2) Lateral movement of stiffening girder caused by wind force during and after construction (3) Global bucking of stiffening girder caused by axial force Among this, the number 3 has not received much attention in the past due to high buckling safety factor of stiffening girder. However, according to be slender of stiffening girder, the topic of buckling stability of girder is not any more unconcerned subject. The purpose of this paper is to examine the effect of stay cable's nonlinear behavior on the buckling stability of cable-stayed bridge.

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Nonlinear Analysis of High Strength Reinforced Concrete Members Considering the Tension Stiffening Model (인장강성 모델을 고려한 고강도 철근콘크리트 부재의 비선형 해석)

  • 홍창우;윤경구;김경진;박제선
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.479-482
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    • 1999
  • The tension stiffening effect, which means the maintaining a part of stiffness after cracking of concrete in tensile, exists at a reinforced concrete member because of the concrete softening and bonding stress between cracks. It is required to consider it for precise analysis and evaluation o structural behavior, due to the possibility of discrepancy between the actual behavior and the analysis without considering the tension stiffening effect. Making and adopting a tension stiffening model is the most simple and effective way for considering it at nonlinear analysis which indicated the estimation from models and experimental results were similar each others. The comparisons on RC beam were, also performed in order to analyzed the influence of concrete strength and steel ratio into the structural behavior. They indicated that the results from analysis estimated quite closely to the test results at low steel ratio, however, overestimated at high steel ratio. The overestimation increase linearly as concrete strength or steel ratio increased.

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Computing the Refined Compression Field Theory

  • Hernandez-Diaz, A.M.;Garcia-Roman, M.D.
    • International Journal of Concrete Structures and Materials
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    • v.10 no.2
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    • pp.143-147
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    • 2016
  • In recent years, some modifications were introduced in the stress-strain relationship of the steel in order to develop a more efficient shear model for reinforced concrete members. The last contribution in this sense corresponding to the Refined Compression Field Theory (RCFT, 2009); this theory proposed a steel constitutive model that has account the tension stiffening area prescribed by technical codes, what simplifies all the design process. However, under certain design conditions supported by such codes, the RCFT model does not provide a real (non-complex) solution for the steel yield strain when the prescribed tension stiffening area is considered; then the load-strain response cannot be computed. In this technical note, the tension stiffening area is fixed in order to guarantee the application of the embedded steel constitutive model for all the standard design range.

An Comparison of an Immediate Deflection according to Tension Stiffening Effect (인장증강효과에 따른 순간 처짐량의 비교)

  • Kim, Young-Jin;Choi, Seung-Won;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.71-72
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    • 2010
  • In case of calculation of an immediate deflection according to EC2, a curvature and average curvature are calculated by reflecting tension stiffening effect. In this study, tension stiffening effects according to MC90 and EC2 were considered, and an immediate deflection was calculated. And also, it was compared to results in KCI provision and experimental data. In results, it has difference around 8~15% with respect to tension stiffening effect, but all of them predict well for the load-deflection behavior after yielding state.

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Investigation of nonlinear behaviour of reinforced concrete frames having different stiffening members

  • Gursoy, Senol
    • Computers and Concrete
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    • v.13 no.5
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    • pp.679-694
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    • 2014
  • The selected carrier systems of reinforced concrete frame buildings are quite important on structural damages. In this study are examined comparatively nonlinear behaviours of reinforced concrete frames which having different stiffening members under a horizontal load. In that respect, the study consists of six parametric models. With this purpose, nonlinear structural analyses of reinforced concrete frames which having different stiffening members were carried out with LUSAS which uses the finite element method. Thus, some conclusions and recommendations to mitigate the damage of reinforced concrete buildings in the future designs are aimed to present. The obtained results revealed that in terms of performance, the x-shaped diagonal elements can be used as an option to shear walls. In addition, it was found that frame-2, frame-3 and frame-4 showed a better performance than traditional frame system (frame-1).