• Title/Summary/Keyword: Reinforcing element

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Simplified Analysis and Design with Finite Element for Reinforced Concrete Shear Walls Using Limit State Equations (한계상태방정식에 의한 R/C 전단벽의 유한요소 간편 해석과 설계)

  • 박문호;조창근;이승기
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.1
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    • pp.43-52
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    • 2003
  • The present study is to investigate the ultimate behavior and limit state design of 2-I) R/C structures, with the changing of crack direction, and the yielding of the reinforcing steel bars, and Is to introduce an algorithm for the limit state design and analysis of 2-D R/C structures, directly from the finite element model. For the design of reinforcement in concrete the limit state design equation is incorporated into finite element algorithm to be based on the pointwise elemental ultimate behavior. It is also introduced a simplified nonlinear analysis algorithm for stress-strain relationship of R/C plane stress problem considering the cracking and its rotation in concrete and the yielding of the reinforcing steel bar. The algorithm is incorporated into the nonlinear finite element analysis. The analysis model is compared with the experimental model of R/C shear wall. In a simple design example for a shear wall, the required reinforcement ratios in each finite element is obtained from the limit state design equations.

A two-phase interface element for simulation of lining systems

  • Liu, X.;Scarpas, A.;Blaauwendraad, J.
    • Structural Engineering and Mechanics
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    • v.11 no.5
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    • pp.547-564
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    • 2001
  • The numerical formulation of a two-phase interface element appropriate for porous lining system is presented. The formulation is isoparametric and can be applied both for 2-D and 3-D analysis. Biot's theory is utilized as the basis for the development of the element constitutive theory. In order to be capable of simulating the reinforcing characteristics of some geotextiles utilized as lining system, a reinforcement component has also been implemented into the formulation. By employing this specially developed interface finite element, the influence of soil consolidation on the stress distribution along the lining system of a reservoir and a landfill has been investigated.

Modelling time-dependent cracking in reinforced concrete using bond-slip Interface elements

  • Chong, Kak Tien;Gilbert, R. Ian;Foster, Stephen J.
    • Computers and Concrete
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    • v.1 no.2
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    • pp.151-168
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    • 2004
  • A two-dimensional nonlinear finite element model is developed to simulate time-dependent cracking of reinforced concrete members under service loads. To predict localized cracking, the crack band model is employed to model individual crack opening. In conjunction with the crack band model, a bond-interface element is used to model the slip between concrete and reinforcing steel permitting large slip displacements between the concrete element nodes and the steel truss element nodes at crack openings. The time-dependent effects of concrete creep and shrinkage are incorporated into the smeared crack model as inelastic pre-strains in an iterative solution procedure. Two test examples are shown to verify the finite element model with good agreement between the model and the observed test results.

Fibered Element for the Three-Dimensional Nonlinear Analysis of Prestressed Concrete Frames (PSC 뼈대의 3차원 비선형 해석을 위한 화이버 모델 요소)

  • 이재석;최규천
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.195-201
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    • 2003
  • A fibered element for the material and geometric nonlinear analysis of three-dimensional reinforced and prestressed concrete frame is presented. The fibered frame element is idealized as an assemblage of concrete and reinforcing steel fibers in order to account for varied material properties within the cross section of the frame element through elastic, cracking and ultimated stages of materials. Prestressing tendon is modeled as an assemblage of multilinear prestressing steel segments each of which spans a frame element. The contribution of each prestressing steel is added directly to the fibered frame element. Numerical results from the ultimate analysis of three-dimensional PSC box girder are compared with those obtained from other investigator. The validity and the capability of the present nonlinear analysis model is well demonstrated.

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Finite Element Analysis of Soil-Reinforced Segmental Retaining Walls Subjected to Earthquake Loading (보강토 옹벽의 지진시 거동에 관한 유한요소해석)

  • 유충식
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.101-108
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    • 2000
  • This paper presents the results of finite element analysis on the seismic response of a soil-reinforced segmental retaining wall subjected to a prescribed earthquake record. The results of finite element analysis indicate that the maximum wall displacement occurs at the top, exhibiting a cantilever type of wall movement. Also revealed is that the increase in reinforcement force is more pronounced in the upper part of the reinforced zone, resulting in a more or less uniform distribution. None of the design guidelines appears to be able to correctly predict the dynamic force increase when compared with the results of finite element analysis. The results demonstrated that there exist critical stiffness and length of reinforcement beyond which further increase would not contribute to additional reinforcing effect. Based on the findings from this study, a number of implications to the current design methods are discussed.

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Numerical Study on the Joints between Precast Post-Tensioned Segments

  • Kim, Tae-Hoon;Kim, Young-Jin;Jin, Byeong-Moo;Shin, Hyun-Mock
    • International Journal of Concrete Structures and Materials
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    • v.19 no.1E
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    • pp.3-9
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    • 2007
  • This paper presents a numerical procedure for analyzing the joints between precast post-tensioned segments. A computer program for the analysis of reinforced concrete structures was run for this problem. Models of material nonlinearity considered in this study include tensile, compressive and shear models for cracked concrete and a model for reinforcing steel with smeared crack. An unbonded tendon element based on the finite element method, that can describe the interaction between the tendon and concrete of prestressed concrete member, was experimentally investigated. A joint element is newly developed to predict the inelastic behavior of the joints between segmental members. The proposed numerical method for the joints between precast post-tensioned segments was verified by comparison of its results with reliable experimental results.

Analysis of RC walls with a mixed formulation frame finite element

  • Saritas, Afsin;Filippou, Filip C.
    • Computers and Concrete
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    • v.12 no.4
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    • pp.519-536
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    • 2013
  • This paper presents a mixed formulation frame element with the assumptions of the Timoshenko shear beam theory for displacement field and that accounts for interaction between shear and normal stress at material level. Nonlinear response of the element is obtained by integration of section response, which in turn is obtained by integration of material response. Satisfaction of transverse equilibrium equations at section includes the interaction between concrete and transverse reinforcing steel. A 3d plastic damage model is implemented to describe the hysteretic behavior of concrete. Comparisons with available experimental data on RC structural walls confirm the accuracy of proposed method.

Influence of Reinforcements on the Chloride Diffusion Analysis of Concrete Structures (철근의 영향을 고려한 콘크리트 구조물의 염소이온 확산해석)

  • 오병환;장봉석;이명규
    • Journal of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.883-891
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    • 2002
  • The chloride penetration in concrete structures is influenced by many factors such as types of cement and admixture proportion. Therefore, the effects of these factors on chloride diffusion must be correctly considered. The conventional diffusion analysis also neglected the existence of reinforcing bar in concrete structures. The purpose of the present paper is therefore to investigate the effect of reinforcing bar on the chloride diffusion in concrete structures. For this purpose, a comprehensive finite element analyses have been conducted to obtain chloride penetration profile. The results indicate that the chlorides are accumulated in front of a reinforcing bar and that the accumulation is much larger for the case of large diameter bars. The higher accumulation of chloride at bar location causes much faster corrosion of reinforcing steel. It can be concluded from the present study that the effects of reinforcing bars must be considered in chloride diffusion analysis for more realistic prediction of durable life of concrete structures.

Collision Characteristics of Arch-Type Submarine Cable Protector - Effect of Material Models (재료모델 변화에 따른 아치형 해저 케이블 보호구조물의 충돌 특성)

  • Woo, Jin-Ho;Na, Won-Bae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.6
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    • pp.609-616
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    • 2011
  • In the study, we analyzed the collision characteristics of a so-called arch-type submarine cable protector by considering the changes in drop heights of a stock anchor and material models for concrete and steel reinforcing bars. We considered plastic kinematics model and Johnson-Holmquist Concrete model for the concrete and linear elastic model and plastic kinematics model for the reinforcing bars. The drop heights of 2-ton stock anchor were selected as 3, 5, and 8.83m, respectively. ANSYS, a finite element analysis program, was used for the collision analysis. To save computational time, we converted those drop heights into initial velocities by the principle of energy conservation. From the sensitivity of the material models on the drop height changes, it is shown that the collision response of the reinforcing bars is sensitive firstly on the steel models and secondly on the concrete models, while the collision response of the concrete is sensitive only on the concrete models.

Displacement Ductility Ratio of Reinforced Concrete Bridge Piers with Lap-splices (주철근 겹침이음 비율에 따른 RC교각의 연성능력 평가)

  • Park, Kwang-Soon;Ju, Hyeong-Seok;Shin, Hyun-Mock;Kim, Moon-Kyum
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.6
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    • pp.1-12
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    • 2008
  • As internal and external seismic experiment results, the seismic performance of RC bridge piers is largely dependent on the ratio of lap-spliced bars to all longitudinal reinforcing bars in plastic hinge regions, and confining effects of transverse reinforcements. Capacity and displacement ductility of non-seismically designed existing RC piers are reduced by lap splices in plastic hinge regions. The provision for the lap splice of longitudinal reinforcing bars was not specified in KBDS (Korean Bridge Design Specifications) before the implementation of 1992 seismic design code, but the ratio of lap-spliced bars to all longitudinal reinforcing bars in plastic hinge regions is restricted to 50% in the 2005 version of KBDS. This paper presents a seismic assessment of RC piers at lap-splicing ratios of 0%, 50%, and 100%. Through a comparison of experimental and analytic results of RC piers, we introduce an appropriate ultimate strain of confined concrete in plastic hinge regions with lap-splices, and propose a method for estimating displacement ductility ratios of non-seismically designed existing RC piers using fiber element analysis.