• 제목, 요약, 키워드: plastic hinge length

검색결과 79건 처리시간 0.033초

Plastic hinge length of circular reinforced concrete columns

  • Ou, Yu-Chen;Kurniawan, Raditya Andy;Kurniawan, Dimas Pramudya;Nguyen, Nguyen Dang
    • Computers and Concrete
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    • v.10 no.6
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    • pp.663-681
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    • 2012
  • This paper presents a parametric study of the plastic hinge length of circular reinforced concrete columns using a three-dimensional finite element analysis method, and using the Taguchi robust design method to reduce computational cost. Parameters examined include the longitudinal reinforcing ratio, the shear span-to-depth ratio, the axial force ratio and the concrete compressive strength. The study considers longitudinal reinforcement with yield strengths of 414 MPa and 685 MPa, and proposes simplified formulas for the plastic hinge length of circular reinforced concrete columns, showing that increases in plastic hinge length correlate to increases in the axial load, longitudinal reinforcing and shear span-to-depth ratios. As concrete strength increases, the plastic hinge length decreases for the 414 MPa case but increases for the 685 MPa case.

철근의 연성이 소성힌지 생성에 미치는 영향 (Influence of ductility of reinforcement on the plastic hinge formation)

  • 박대균;조재열;박성현
    • 한국콘크리트학회:학술대회논문집
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    • pp.97-100
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    • 2008
  • 최근 들어 고강도 철근의 사용이 증가하고 있지만, 지진위험이 있는 지역의 내진구조물에 있어서는 고강도 철근의 취성적 성질로 인해 그 사용이 제한되어 왔다. 그러나, 철근의 연성의 변화가 기둥의 부재레벨의 연성도에 미치는 영향에 대해서는 많은 연구가 없는 실정이다. 특히 고강도 철근을 사용하는 경우 철근의 연성의 변화로 인해 부재의 소성힌지 길이가 달라질 것으로 예상되지만, 기준의 소성힌지길이 산정식은 철근 등 재료의 특성을 고려하지 못하고 있다. 지진하중을 받는 철근콘크리트 기둥의 소성힌지길이는 실험을 통해서 측정하기는 어려움이 많다. 따라서, 본 논문에서는 해석적인 방법을 통하여 재료레벨의 연성, 특히 철근의 연성이 소성힌지의 생성에 미치는 영향을 평가하고, 그 영향을 고려한 소성힌지길이 산정식을 제안하고자 한다.

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The length of plastic hinge area in the flanged reinforced concrete shear walls subjected to earthquake ground motions

  • Bafti, Farzad Ghaderi;Mortezaei, Alireza;Kheyroddin, Ali
    • Structural Engineering and Mechanics
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    • v.69 no.6
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    • pp.651-665
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    • 2019
  • Past earthquakes have shown that appropriately designed and detailed buildings with shear walls have great performance such a way that a considerable portion of inelastic energy dissipation occurs in these structural elements. A plastic hinge is fundamentally an energy diminishing means which decrease seismic input energy through the inelastic deformation. Plastic hinge development in a RC shear wall in the areas which have plastic behavior depends on the ground motions characteristics as well as shear wall details. One of the most generally used forms of structural walls is flanged RC wall. Because of the flanges, these types of shear walls have large in-plane and out-of-plane stiffness and develop high shear stresses. Hence, the purpose of this paper is to evaluate the main characteristics of these structural components and provide a more comprehensive expression of plastic hinge length in the application of performance-based seismic design method and promote the development of seismic design codes for shear walls. In this regard, the effects of axial load level, wall height, wall web and flange length, as well as various features of earthquakes, are examined numerically by finite element methods and the outcomes are compared with consistent experimental data. Based on the results, a new expression is developed which can be utilized to determine the length of plastic hinge area in the flanged RC shear walls.

소성힌지가 기둥면에서 이동된 RC보의 이력거동 해석모델 (Development of Hysteretic Analysis Model for RC beam with Relocated Plastic Hinge from Column Face)

  • 서수연;윤승조;이리형;권영준
    • 한국구조물진단유지관리공학회 논문집
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    • v.6 no.3
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    • pp.167-175
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    • 2002
  • In this paper, an analytical model is proposed for analyzing the hysteretic behavior of RC beam with relocated plastic hinge region under load reversals. The plastic hinge is modeled not to be concentrated on a point but to be distributed on a finite size in beam. This is based on the assumption that the plastic hinge is formed over a certain region, in which the curvature varies. Tangential matrix is reformed using stiffness coefficients including variales such as the length and location of plastic hinge region. In order to construct the hysteretic rule of hinge, modified Takeda rule is also proposed on the base of regression analysis for the previous test results. Previous specimens are analyzed using the proposed model and the result is compared with test result. On the result of the comparison, it was shown that the hysteretic behavior of beams with different location of plastic hinge region could be prediced using the proposed analytical process.

2주형 다주교각의 연성도 및 소성힌지 영역에 관한 연구 (Assessment of Ductility and Plastic Hinge Region of Reinforced Concrete Multi-Column Bent)

  • 변순주;임정순
    • 한국방재학회 논문집
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    • v.6 no.3
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    • pp.37-45
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    • 2006
  • 다주교각의 횡방향 철근비에 따른 연성도 및 소성힌지 영역을 단주교각과 비교하여 평가하였다. 횡방향 철근비가 높을수록 연성도 증가는 뚜렷하며 다주교각의 경우 교축직각방향 거동시에는 단주보다 더 큰 연성도 증가를 보였다. 또한 횡철근 배근을 위한 소성힌지영역을 산정하였으며 목표연성도를 크게 할수록 횡구속 철근비의 증가와 함께 횡구속 되어야 하는 소성힌지영역 또한 높아져야함을 밝혔다. 다주교각의 방향별 거동에 따른 소성힌지 영역에는 차이가 있으며, 다주교각의 교축직각방향 거동시에는 모멘트 분포의 차이에 의해 보다 낮은 구간에서 소성변형을 보인다.

Experimental research on the propagation of plastic hinge length for multi-scale reinforced concrete columns under cyclic loading

  • Tang, Zhenyun;Ma, Hua;Guo, Jun;Xie, Yongping;Li, Zhenbao
    • Earthquakes and Structures
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    • v.11 no.5
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    • pp.823-840
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    • 2016
  • The plastic hinge lengths of beams and columns are a critical demand parameter in the nonlinear analysis of structures using the finite element method. The numerical model of a plastic hinge plays an important role in evaluating the response and damage of a structure to earthquakes or other loads causing the formation of plastic hinges. Previous research demonstrates that the plastic hinge length of reinforced concrete (RC) columns is closely related to section size, reinforcement ratio, reinforcement strength, concrete strength, axial compression ratio, and so on. However, because of the limitations of testing facilities, there is a lack of experimental data on columns with large section sizes and high axial compression ratios. In this work, we conducted a series of quasi-static tests for columns with large section sizes (up to 700 mm) and high axial compression ratios (up to 0.6) to explore the propagation of plastic hinge length during the whole loading process. The experimental results show that besides these parameters mentioned in previous work, the plastic hinge of RC columns is also affected by loading amplitude and size effect. Therefore, an approach toward considering the effect of these two parameters is discussed in this work.

Increasing plastic hinge length using two pipes in a proposed web reduced beam section, an experimental and numerical study

  • Zahrai, Seyed M.;Mirghaderi, Seyed R.;Saleh, Aboozar
    • Steel and Composite Structures
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    • v.23 no.4
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    • pp.421-433
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    • 2017
  • Experimental and numerical studies of a newly developed Reduced Beam Section (RBS) connection, called Tubular Web RBS connection (TW-RBS) have been recently conducted. This paper presents experimental and numerical results of extending the plastic hinge length on the beam flange to increase energy dissipation of a proposed version of the TW-RBS connection with two pipes, (TW-RBS(II)), made by replacing a part of flat web with two steel tubular web at the desirable location of the beam plastic hinge. Two deep-beam specimens with two pipes are prepared and tested under cyclic loads. Obtained results reveal that the TW-RBS(II) like its type I, increases story drift capacity up to 6% in deep beam much more than that stipulated by the current seismic codes. Based on test results, the proposed TW-RBS(II) helps to dissipate imposed energy up to 30% more than that of the TW-RBS(I) specimens at the same story drift and also reduces demands at the beam-to-column connection up to 30% by increasing plastic hinge length on the beam flange. The TW-RBS(II) specimens are finally simulated using finite element method showing good agreement with experimental results.

Sensitivity analysis of the plastic hinge region in the wall pier of reinforced concrete bridges

  • Babaei, Ali;Mortezaei, Alireza;Salehian, Hamidreza
    • Structural Engineering and Mechanics
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    • v.72 no.6
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    • pp.675-687
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    • 2019
  • As the bridges are an integral part of the transportation network, their function as one of the most important vital arteries during an earthquake is fundamental. In a design point of view, the bridges piers, and in particular the wall piers, are considered as effective structural elements in the seismic response of bridge structures due to their cantilever performance. Owing to reduced seismic load during design procedure, the response of these structural components should be ductile. This ductile behavior has a direct and decisive correlation to the development of plastic hinge region at the base of the wall pier. Several international seismic design codes and guidelines have suggested special detailing to assure ductile response in this region. In this paper, the parameters which affect the length of plastic hinge region in the reinforced concrete bridge with wall piers were examined and the sensitivity of these parameters was evaluated on the length of the plastic hinge region. Sensitivity analysis was accomplished by independently variable parameters with one standard deviation away from their means. For this aim, the Monte Carlo simulation, tornado diagram analysis, and first order second moment method were used to determine the uncertainties associated with analysis parameters. The results showed that, among the considered design variables, the aspect ratio of the pier wall (length to width ratio) and axial load level were the most important design parameters in the plastic hinge region, while the yield strength of transverse reinforcements had the least effect on determining the length of this region.

Plastic hinge length of RC columns considering soil-structure interaction

  • Mortezaei, Alireza
    • Earthquakes and Structures
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    • v.5 no.6
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    • pp.679-702
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    • 2013
  • During an earthquake, soils filter and send out the shaking to the building and simultaneously it has the role of bearing the building vibrations and transmitting them back to the ground. In other words, the ground and the building interact with each other. Hence, soil-structure interaction (SSI) is a key parameter that affects the performance of buildings during the earthquakes and is worth to be taken into consideration. Columns are one of the most crucial elements in RC buildings that play an important role in stability of the building and must be able to dissipate energy under seismic loads. Recent earthquakes showed that formation of plastic hinges in columns is still possible as a result of strong ground motion, despite the application of strong column-weak beam concept, as recommended by various design codes. Energy is dissipated through the plastic deformation of specific zones at the end of a member without affecting the rest of the structure. The formation of a plastic hinge in an RC column in regions that experience inelastic actions depends on the column details as well as soil-structure interaction (SSI). In this paper, 854 different scenarios have been analyzed by inelastic time-history analyses to predict the nonlinear behavior of RC columns considering soil-structure interaction (SSI). The effects of axial load, height over depth ratio, main period of soil and structure as well as different characteristics of earthquakes, are evaluated analytically by finite element methods and the results are compared with corresponding experimental data. Findings from this study provide a simple expression to estimate plastic hinge length of RC columns including soil-structure interaction.

휨 항복형 철근콘크리트 전단벽의 등가소성힌지길이 모델 (Equivalent Plastic Hinge Length Model for Flexure-Governed RC Shear Walls)

  • 문주현;양근혁
    • 한국구조물진단유지관리공학회 논문집
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    • v.18 no.2
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    • pp.1-8
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    • 2014
  • 본 연구의 목적은 경계요소를 갖는 철근콘크리트 전단벽의 잠재소성힌지길이를 합리적으로 평가할 수 있는 단순모델의 제시이다. 전단벽의 높이에 따른 이상화된 곡률분포로부터, 기본방정식은 항복모멘트와 최대모멘트 그리고 사인장균열에 의한 부가모멘트의 함수로 일반화되었다. 전단벽의 항복모멘트와 최대모멘트는 변형률 적합조건과 힘의 평형조건을 기반하여 산정하였다. 사인장균열 발생의 여부는 ACI 318-11에서 제시된 콘크리트의 전단력으로부터 검토되었으며, 부가모멘트는 Park and Paulay에 의해 제시된 트러스기구를 이용하여 산정하였다. 이들 모멘트식들은 다양한 변수범위에서 변수연구를 수행하였다. 결과적으로 등가소성힌지길이는 주철근 및 수직철근지수와 축력지수의 함수로 제시될 수 있었다. 제시된 등가소성힌지길이의 모델은 실험결과의 비교에서 평균 및 표준편차가 각각 1.019와 0.102로 실험 결과를 정확하게 예측하였다.