• Title/Summary/Keyword: hysteretic model

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Dynamic Response Analysis of R/C Frame Structures Using High-Strength Concrete (고강도 콘크리트를 사용한 R/C 평면골조의 동적응답해석)

  • 장극관;황정현;방세용
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.278-286
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    • 2001
  • The purpose of this paper is to suggest an analytical technique for time history analysis of R/C frame structure using high-strength concrete under seismic loading. Current researches in hysteretic model of structral elements using high-strength concrete are not enough. It is the cause of error that apply hysteretic model of element using normal-strength concrete to the inelastic analysis of high-strength concrete R/C frame structures. In this paper time history analysis using IDARC and DRAIN programs was performed for a 2-bay, 20-story R/C frame structures. Particularly nonlinear dynamic analysis was performed by IDARC program that was applied hysteretic model of structural element using high-strength concrete. centro earthquake 1940 NS waves was used in the analysis and its peak ground accelerations are changed to be 0.12g, 0.25g

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Seismic performance assessment of steel reinforced concrete members accounting for double pivot stiffness degradation

  • Juang, Jia-Lin;Hsu, Hsieh-Lung
    • Steel and Composite Structures
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    • v.8 no.6
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    • pp.441-455
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    • 2008
  • This paper presents an effective hysteretic model for the prediction and evaluation of steel reinforced concrete member seismic performance. This model adopts the load-deformation relationship acquired from monotonic load tests and incorporates the double-pivot behavior of composite members subjected to cyclic loads. Deterioration in member stiffness was accounted in the analytical model. The composite member performance assessment control parameters were calibrated from the test results. Comparisons between the cyclic load test results and analytical model validated the proposed method's effectiveness.

Energy-Based Hysteretic Models for R/C Members (에너지 소산능력에 기초한 철근콘크리트 부재의 이력모델)

  • Eom, Tae-Sung;Park, Hong-Gun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.5
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    • pp.45-54
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    • 2004
  • Since existing hysteretic models for R/C members focused on presenting the degrading stiffness using empirical equations based on experiments, they cannot accurately predict the energy dissipation capacity during cyclic loading. Recently, design equations which can evaluate the energy dissipation capacity of R/C members were developed. Based on those equations, in the present study, an energy-based hysteretic model for flexure-dominated R/C members was developed. The proposed model was devised to dissipate the same energy as the actual one dissipated during a complete load cycle. The proposed model represents the hysteretic behaviors of R/C members accompanied by stiffness degradation and pinching using primary and cyclic curves and six unloading/reloading rules. The proposed model was verified by comparisons with various experimental results. The energy-based hysteretic model can be used to develop computer programs for static and dynamic analysis/design because it is simple and easily applicable to numerical analysis.

Fragility analysis of R/C frame buildings based on different types of hysteretic model

  • Borekci, Muzaffer;Kircil, Murat S.
    • Structural Engineering and Mechanics
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    • v.39 no.6
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    • pp.795-812
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    • 2011
  • Estimation of damage probability of buildings under a future earthquake is an essential issue to ensure the seismic reliability. Fragility curves are useful tools for showing the probability of structural damage due to earthquakes as a function of ground motion indices. The purpose of this study is to compare the damage probability of R/C buildings with low and high level of strength and ductility through fragility analysis. Two different types of sample buildings have been considered which represent the building types mentioned above. The first one was designed according to TEC-2007 and the latter was designed according to TEC-1975. The pushover curves of sample buildings were obtained via pushover analyses. Using 60 ground motion records, nonlinear time-history analyses of equivalent single degree of freedom systems were performed using bilinear hysteretic model and peak-oriented hysteretic model with stiffness - strength deterioration for each scaled elastic spectral displacement. The damage measure is maximum inter-story drift ratio and each performance level considered in this study has an assumed limit value of damage measure. Discrete damage probabilities were calculated using statistical methods for each considered performance level and elastic spectral displacement. Consequently, continuous fragility curves have been constructed based on the lognormal distribution assumption. Furthermore, the effect of hysteresis model parameters on the damage probability is investigated.

Effect of Stiffness and Strength Degrading Model on Evaluating the Response Modification Factor (강성 및 강도저하 모델이 반응수정계수 산정에 미치는 영향 평가)

  • 오영훈;한상환;이리형
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.25-32
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    • 1998
  • Most recent seismic design codes include Response Modification Factor(RMF) for determining equivalent lateral forces. The RMF is used to reduce the linear elastic design spectrum to account for the energy dissipation capacity, overstrength and damping of the structure. In this study the RMF is defined as the ratio of the absolute maximum linear elastic base shear to the absolute maximum nonlinear base shear of a structure subject to the same earthquake accelerogram. This study investigates the effect of hysteretic model, as well as target ductility ratio and natural period on duct based RMF using nonlinear dynamic analyses of the SDOF systems. Special emphasis is given to the effects of the hysteretic characteristics such as strength deterioration and stiffness degradation. Results indicate that RMFs are dependent on ductility, period and hysteretic model.

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Analytic Hysteretic Model of Reinforced Concrete Members (철근콘크리트 부재의 해석적 이력모델)

  • 정영수
    • Computational Structural Engineering
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    • v.4 no.1
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    • pp.133-142
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    • 1991
  • A mathematical hysteretic model has been developed to analytically reproduce the experimental hysteretic behavior of reinforced concrete members. This mode[2, 3] can simulate the nonlinear response of reinforced concrete members with sufficient accuacy, which are characterized by following important hysteretic behaviors: stiffness degradation, strength deterioration and shear effect. In order to illustrate the capabilities of the proposed mathematical model, numerical examples are presented with the reproduction of experimental hysteretic behavior of RC members and frames.

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Effects of strong ground motions of near source earthquakes on response of thin-walled L-shaped steel bridge piers

  • Xie, Guanmo;Taniguchi, Takeo;Chouw, Nawawi
    • Structural Engineering and Mechanics
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    • v.12 no.3
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    • pp.341-346
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    • 2001
  • Near source earthquakes can be characterized not only by strong horizontal but also by strong vertical ground motions with broad range of dominant frequencies. The inelastic horizontal response of thin-walled L-shaped steel bridge piers, which are popularly used as highway bridge supports, subjected to simultaneous horizontal and vertical ground excitations of near source earthquakes is investigated. A comprehensive damage index and an evolutionary-degrading hysteretic model are applied. Numerical analysis reveals that the strong vertical excitation of a near source earthquake exerts considerable influences on the damage development and horizontal response of thin-walled L-shaped steel bridge piers.

Variations of Coefficient of Earth Pressure at Rest According to Stress Paths for Compacted Residual Soils (다짐 화강풍화토의 응력이력에 따른 정지상태 토압계수의 변화)

  • Lee Byung-Sik;Park Sung-Kook
    • Journal of the Korean Geotechnical Society
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    • v.21 no.8
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    • pp.85-93
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    • 2005
  • Earth pressures acting on unmovable rigid walls vary according to loading-unloading conditions due to compaction experienced by backfill soil. Appropriate coefficients of earth pressure at rest with considering this influence need to be determined to estimate earth pressures more reasonably.0 this study, a single cycle hysteretic model simulating soil's loading-unloading-reloading behavior under $K_o-condition$ was reproduced by conducting a series of $K_o-triaxial$ test for compacted residual soils. Based on the results, coefficients of earth pressure at rest at each stage of stress paths such as, virgin loading, unloading and reloading were determined. Also, applicabilities of empirical equations to the estimation of the coefficients were evaluated by comparing the experimental results with those estimated by the equations. As a result, it was concluded that the empirical equations could be applied reasonably to the estimation of the coefficients for compacted residual soils in cases where some amount of error might be acceptable for the reloading stage of the hysteretic model.

Behaviour of lightweight aggregate concrete-filled steel tube under horizontal cyclic load

  • Fu, Zhongqiu;Ji, Bohai;Wu, Dongyang;Yu, Zhenpeng
    • Steel and Composite Structures
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    • v.32 no.6
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    • pp.717-729
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    • 2019
  • A horizontal cyclic test was carried out to study the seismic performance of lightweight aggregate concrete filled steel tube (LACFST). The constitutive and hysteretic model of core lightweight aggregate concrete (LAC) was proposed for finite element simulation. The stress and strain changes of the steel tube and concrete filled inside were measured in the experiment, and the failure mode, hysteresis curve, skeleton curve, and strain curve of the test specimens were obtained. The influence of axial compression ratio, diameter-thickness ratio and material strength were analysed based on finite element model. The results show that the hysteresis curve of LACFST indicated favourable ductility, energy dissipation, and seismic performance. The LACFST failed when the concrete in the bottom first crushed and the steel tube then bulged, thus axial force imposed by prestressing was proved to be feasible. The proposed constitutive model and hysteretic model of LAC under the constraint of its steel tube was reliable. The bearing capacity and ductility of the specimen increase significantly with increasing thickness of the steel tube. The bearing capacity of the member improves while the ductility and energy dissipation performance slightly decreased with the increasing strength of the steel and concrete.

Performance evaluation and hysteretic modeling of low rise reinforced concrete shear walls

  • Nagender, T.;Parulekar, Y.M.;Rao, G. Appa
    • Earthquakes and Structures
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    • v.16 no.1
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    • pp.41-54
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    • 2019
  • Reinforced Concrete (RC) shear walls are widely used in Nuclear power plants as effective lateral force resisting elements of the structure and these may experience nonlinear behavior for higher earthquake demand. Short shear walls of aspect ratio less than 1.5 generally experience combined shear flexure interaction. This paper presents the results of the displacement-controlled experiments performed on six RC short shear walls with varying aspect ratios (1, 1.25 and 1.5) for monotonic and reversed quasi-static cyclic loading. Simulation of the shear walls is then carried out by Finite element modeling and also by macro modeling considering the coupled shear and flexure behaviour. The shear response is estimated by softened truss theory using the concrete model given by Vecchio and Collins (1994) with a modification in softening part of the model and flexure response is estimated using moment curvature relationship. The accuracy of modeling is validated by comparing the simulated response with experimental one. Moreover, based on the experimental work a multi-linear hysteretic model is proposed for short shear walls. Finally ultimate load, drift, ductility, stiffness reduction and failure pattern of the shear walls are studied in details and hysteretic energy dissipation along with damage index are evaluated.