• Title/Summary/Keyword: Transverse beam

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Retrofitting reinforced concrete beams by bolting steel plates to their sides -Part 2: Transverse interaction and rigid plastic design

  • Oehlers, Deric John;Ahmed, Marfique;Nguyen, Ninh T.;Bradford, Mark Andrew
    • Structural Engineering and Mechanics
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    • v.10 no.3
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    • pp.227-243
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    • 2000
  • In a companion paper, tests on bolted side plated beams have shown that side plates can substantially increase the strength of existing reinforced concrete beams with little if any loss of ductility and, furthermore, induce a gradual mode of failure after commencement of concrete crushing. However, it was also shown that transverse interaction between the side plates and the reinforced concrete beam, that is vertical slip and which is a concept unique to side plated beams, is detrimental. Transverse interaction increases the forces on the bolt shear connectors and, hence, weakens the beam. It also reduces the ability of the composite plated beam to yield and, hence, to attain its full flexural capacity. The generic concept of transverse interaction will be described in this paper and the results used to develop a new form of rigid plastic analysis for bolted side plated beams which is illustrated with an application.

A piecewise linear transverse shear transfer model for bolted side-plated beams

  • Li, Ling-Zhi;Jiang, Chang-Jiu;Su, Ray Kai-Leung;Lo, Sai-Huen
    • Structural Engineering and Mechanics
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    • v.62 no.4
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    • pp.443-453
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    • 2017
  • The performance of bolted side-plated (BSP) beams is affected by the degree of transverse partial interaction, which is a result of the interfacial slip caused by transverse shear transfer between the bolted steel plates and the reinforced concrete beams. However, explicit formulae for the transverse shear transfer profile have yet to be derived. In this paper, a simplified piecewise linear shear transfer model was proposed based on force superposition principle and simplification of shear transfer profiles derived from a previous numerical study. The magnitude of shear transfer was determined by force equilibrium and displacement compatibility condition. A set of design formulae for BSP beams under several basic load cases was also derived. Then the model was verified by test results. A worked example was also provided to illustrate the application of the proposed design formulae. This paper sheds some light on the shear force transfer mechanism of anchor bolts in BSP beams, and offers a practical method to evaluate the influence of transverse partial interaction in strengthening design.

Locking-free Straight Beam Element by a Modified Transverse Displacement Field (수정 횡변위장에 의한 강성과잉이 없는 직선 보 요소)

  • 이팔갑;신효철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.12
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    • pp.2287-2297
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    • 1992
  • The Formulation of a new Hermite straight beam element to eliminate the shear locking is presented. All the kinematic variables in Timoshenko beam are reinterpreted by the consideration of equilibrium equations together. It shows that when the modified transverse displacement field is used the Timoshenko beam looks apparently the same as the Euler beam. The element is formulated for the modified transverse displacement field to have the same interpolation scheme as that in the Hermite element. Transformation Matrix which relates a modified nodal vector with nonmodified one is also introduced to deal with general boundary conditions. Several examples are demonstrated and discussed for the purpose of verification of the concepts employed. The solutions obtained reveal that the element describes of the beam quite correctly, showing no locking and that it is also applicable to the analysis of both thin and thick beams.

Dynamic bending analysis of laminated porous concrete beam reinforced by nanoparticles considering porosity effects

  • Karegar, Mohammad;Bidgoli, Mahmood Rabani;Mazaheri, Hamid
    • Steel and Composite Structures
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    • v.43 no.1
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    • pp.129-137
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    • 2022
  • Dynamic response 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.

Vibration Analysis of a Beam Having n Through-the-width Splits (다수의 층상균열이 내재하는 보의 진동해석)

  • Hwang, J.K.;Lee, M.H.;Shin, Y.J.;Kim, C.H.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.5
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    • pp.330-337
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    • 2002
  • A frequency equation of beam subjected to the axial load and having ηthrough-the-width-splits is developed. The beam comprises of beam elements that are split into the upper and the lower part, and non-split beam elements. Equations of motion of each beam element are non-dimensionalized with respect to length. The frequency equation of beam is derived from that of each beam element, which satisfies the displacement of the longitudinal and transverse vibration and the boundary conditions between the beam elements. Numerical simulation and experimental work for the beam having several split beam elements are carried out to demonstrate the analytical development and its validity. The experimental results are in good agreement with those of the present frequency equation. The relationships between the split beam width and natural frequencies, and also the relationships between number of split and natural frequencies, in case that the total beam split length is same. are discussed.

A Study on the Effect of Steel Fiber in Reinforced Concrete Coupling Beam Subjected to Cyclic Loading (반복하중을 받는 철근콘크리트 연결보에서 강섬유의 보강효과에 관한 연구)

  • Kim, Jin-Sung;Bae, Baek-Il;Choi, Chang-Sik
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.10
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    • pp.181-190
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    • 2019
  • In this study, four reinforced concrete coupling beams were subjected to cyclic lateral loading test to evaluate the structural performance of coupling beam according to volume fraction of steel fiber. For this purpose, the volume fraction of steel fiber(0%, 1%, 2%) and transverse reinforcement spacing were determined as the main parameter. According to the test results, the maximum strength of D-40C-s100-0 was 1.15, 1.13, 1.05 times higher than D-40C-s300-0, D-40C-s300-1, D-40C-s300-2, respectively. The maximum strength of coupling beams with mitigated rebar details increases as the volume fraction of steel fiber increases. Although steel fiber 2% reinforced specimen(D-40C-s300-2) did not satisfy the amount of transverse reinforcement required for seismic design of coupling beam, the overall performance including to maximum strength, ductility and energy dissipation capacity was similar to the control specimen(D-40C-s100-0). As a result, the use of steel fiber with 2% reinforcement can partially replace the transverse reinforcement in diagonally reinforced concrete coupling beam.

Zeroth-Order Shear Deformation Micro-Mechanical Model for Periodic Heterogeneous Beam-like Structures

  • Lee, Chang-Yong
    • Journal of Power System Engineering
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    • v.19 no.3
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    • pp.55-62
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    • 2015
  • This paper discusses a new model for investigating the micro-mechanical behavior of beam-like structures composed of various elastic moduli and complex geometries varying through the cross-sectional directions and also periodically-repeated along the axial directions. The original three-dimensional problem is first formulated in an unified and compact intrinsic form using the concept of decomposition of the rotation tensor. Taking advantage of two smallness of the cross-sectional dimension-to-length parameter and the micro-to-macro heterogeneity and performing homogenization along dimensional reduction simultaneously, the variational asymptotic method is used to rigorously construct an effective zeroth-order beam model, which is similar a generalized Timoshenko one (the first-order shear deformation model) capable of capturing the transverse shear deformations, but still carries out the zeroth-order approximation which can maximize simplicity and promote efficiency. Two examples available in literature are used to demonstrate the consistence and efficiency of this new model, especially for the structures, in which the effects of transverse shear deformations are significant.

Finite Element Structural Analysis of Open-Section Composite Beams Considering Transverse Shear (전단변형을 고려한 개방형 단면 복합재료 보의 유한요소 구조해석)

  • 정성남
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.11a
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    • pp.161-164
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    • 2000
  • In this paper, a finite element structural analysis for thin-walled open-section composite beams with elastic couplings has been performed. The analysis includes the effects of transverse shear across beam sections, torsion warping and constrained warping. Reissner's semi-complementary energy functional is used to obtain the beam st illness coefficients The bending and torsion related warpings and the shear correct ion factors are obtained as part of the analysis. The resulting theory describes the beam kinematics in terms of the axial, flap and lag bending, flap and lag shear, torsion and torsion-warping deformations. The static response has been validated against finite element predict ions, closed form solutions, and experimental data for rectangular sol id and I-beams with elastic couplings. The free vibration results are also compared with available literature.

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Shear Strength Equation for Slender Diagonally Reinforced Coupling Beam (세장한 대각보강 연결보의 전단강도 예측식)

  • Han, Sang Whan;Kang, Jin Wook;Han, Chan Hee
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.6
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    • pp.361-368
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    • 2016
  • Coupling beams serve as primary source of energy dissipation in coupled shear wall systems during large earthquakes. However, the overestimation of the shear strength of diagonally reinforced coupling beams may be adverse effect on the seismic performance of coupled shear wall systems. In order to force coupling beams to properly work during earthquakes, coupling beams should be designed with accurate shear strength equations. The objective of this study is to propose the accurate shear strength equation for slender diagonally reinforced coupling beams. For this purpose, experimental tests were conducted using three diagonally reinforced coupling specimens with different amount of transverse reinforcement under reversed cyclic loads to evaluate the hysteretic behavior of the specimens. The test results show that transverse reinforcement of slender diagonally reinforced coupling beam affects the maximum strength and drift ratio.