• Title/Summary/Keyword: time-history analysis

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Using integrated displacement method to time-history analysis of steel frames with nonlinear flexible connections

  • Hadianfard, M.A.
    • Structural Engineering and Mechanics
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    • v.41 no.5
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    • pp.675-689
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    • 2012
  • Most connections of steel structures exhibit flexible behaviour under cyclic loading. The flexible connections can be assumed as nonlinear rotational springs attached to the ends of each beam. The nonlinear behaviour of the connections can be considered by suitable moment-rotation relationship. Time-history analysis by direct integration method can be used as a powerful technique to determine the nonlinear dynamic response of the structure. In conventional numerical integration, the response is evaluated for a series of short time increments. The limitations on the size of time intervals can be removed by using Chen and Robinson improved time history analysis method, in which the integrated displacements are used as the new variables in integrated equation of motion. The proposed method permits longer time intervals and reduces the computational works. In this paper the nonlinearity behaviour of the structure is summarized on the connections, and the step by step improved time-history analysis is used to calculate the dynamic response of the structure. Several numerical calculations which indicate the applicability and advantages of the proposed methodology are presented. These calculations illustrate the importance of the effect of the nonlinear behaviour of the flexible connections in the calculation of the dynamic response of steel frames.

A Method of Selecting Ground Motions for Three-Dimensional Dynamic Analysis of Structures (구조물의 3차원 시간이력해석을 위한 지진파 결정 방법)

  • Ha, Seong Jin
    • Journal of the Architectural Institute of Korea
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    • v.36 no.8
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    • pp.145-151
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    • 2020
  • Dynamic analyses such as response spectrum analysis or time history analysis of structures have been performed to assess the structural demands for earthquake loads. For time history analysis, it is very important to select appropriate input ground motions with construction of numerical models of structures that reflects the non-linearity of the structure. In particular, three-dimensional dynamic analyses are required for skyscrapers or irregular buildings, according to seismic design codes. Current seismic design codes require that two-dimensional time history analysis of a structure should be analyzed using three or more horizontal component ground motions. For three-dimensional analysis, at least three seismic records each consisting of two horizontal components are required. In this study, a method of selecting ground motions for three-dimensional time history analysis of structures was developed in accordance with the criteria of seismic design code. In the method, the square roots of sum of squares for selected response spectra are very similar to the shape and size of the design spectrum. Also, the algorithm is simple, so takes a few seconds for selecting input ground motions. The proposed method is applicable to all target spectra which has only mean spectrum, such as design spectrum, uniform hazard spectrum or conditional spectrum.

The Estimation of the Floor Vibration in Structure for Application of Response Spectrum Analysis Method (응답스펙트럼 해석법을 이용한 건축 구조물의 바닥진동해석)

  • 이동근;김태호
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.4
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    • pp.169-178
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    • 1998
  • In general, the response spectrum analysis method is widely used for seismic analysis of building structures, and the time history analysis is applied for computation of structural vibration caused by equipments, machines and moving loads, etc. However, compared with the response spectrum analysis method, the time history method is very complex, difficult and time consuming. In this study, the maximum responses for the vertical vibration are calculated conveniently by the response spectrum method. At first, Response spectrum and time history analysis for some earthquake excitations are carried out, and the accuracy of maximum displacements obtained from response spectrum analysis is investigated. Secondly, the process for the response spectrum analysis in excitation is calculated, and the maximum modal responses are combined by CQC method. Finally, results of the proposed method are compared with those of the time history analysis.

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Seismic Analysis of 3D-Truss by Response Spectrum (응답스펙트럼에 의한 트러스 구조물의 내진해석)

  • 안주옥;이승재
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.159-168
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    • 1999
  • In seismic analysis, there are two main ways - uniform load method and dynamic analysis, dynamic analysis can be divided into response spectrum analysis and time history analysis. In case of which get the complexion of the vibration with 3-axis of coordinate direction in each mode of free vibration mode happened owing to complication of the shape, 3-dimensional dynamic analysis is recommended to perform as multi-mode spectral analysis in standard specification for highway bridge. The purpose of this study is to understand the dynamic behavior by performing multi-mode seismic analysis according to responses analysis and time history anal)'sis in using record of earthquake. In accordance with the criterion of seismic design as defined in standard specification for highway bridge by using modified records of the El Centre and Coyote Lake earthquake, response spectrum was constructed by using the tripartite logarithmic plot. The 3-span continuous space truss bridge was selected as model of numerical analysis. As the result performed time history analysis and analysis of response spectrum for the model of numerical analysis, the result of time history analysis was slightly larger than that of response spectrum analysis. This coincide with the tendency of the result came from the analysis when using a jagged response spectrum analysis, This coincide with the tendency of the result came from the analysis when using a jagged response spectrum for a single excitation. In the Process of performing these two analysis. response spectrum analysis is more effective than time history analysis in saving times in analyzing data.

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Seismic Perfomance Evaluation of Wind-Designed Steel Highrise Buildings Based on Linear Dynamic Analysis (내풍설계된 철골조 초고층건물의 선형동적해석에 의한 내진성능평가)

  • Lee Cheol-Ho;Kim Seon-Woong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.652-659
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    • 2005
  • Even in moderate to low seismic regions like Korean peninsular where wind loading usually governs the structural design of a tall building, the probable structural impact of the design basis earthquake or the maximum credible earthquake on the selected structural system should be considered at least in finalizing the design. In this study, by using response spectrum analysis and linear time history analysis method, seismic performance evaluation was conducted for wind-designed concentrically braced steel highrise buildings. Both spectrum-compatible artificial accelerograms and recorded accelerograms were used as input ground motions for the time history analysis. The analysis results showed that wind-designed concentrically braced steel highrise buildings possess significantly increased elastic seismic capacity due to the system overstrength resulting from the wind-serviceability criterion and the width-to-thickness ratio limits on steel members. Time history analysis results generally tended to underestimate the seismic response as compared to those of response spectrum analysis.

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Nonlinear Dynamic Response of Well-Slab Apartment Building Considering The Behavior of Coupling Elements (벽식 아파트 구조에서 연결부재의 거동특성을 고려한 비선형 동적 응답)

  • 김기현;장극관;서대원;천영수
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.437-442
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    • 2002
  • The purpose of this study is to investigate nonlinear behavior and estimate ultimate resistance of the wall structure against seismic loading. Experimental data for RC coupling elements are used for specifying the strength deterioration and stiffness degradation factor of hysteretic model. Modified coupling element models are used in the push over analysis and time history analysis. In the time history analysis, three earthquake waves are used in the analysis and their peak ground accelerations are changed to be 0.2g. The conclusions of this study are as follows : (1) In the push over analysis, yielding of coupling elements occurred at lower story with small story drift ratio as 0.3%. (2) In the time history analysis, the story drift ratio is sufficient for the requirement of Korean Code, But coupling elements at most stories of the buildings occurred yielding. i. e. the earthquake resistant capacity of shear wall structures is not sufficient at 0.2g.

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A study on characteristics of blast vibration waveform by vibration time history analysis (진동이력분석을 응용한 발파 진동파형의 특성에 관한 연구)

  • 김진수;임한욱
    • Tunnel and Underground Space
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    • v.9 no.1
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    • pp.36-47
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    • 1999
  • For cautious controlled blasting, it is necessary to understand characteristics of the blasting vibration. In this study, a series of tests were carried out to investigate the several characteristics of blasting vibration waveform by vibration time history analysis. Separation between impulse vibration and free vibration from blasting vibration, duration time, effects of overlap of free vibration upon the level of vibration and changes of waveform according to increase of charge weight per delay etc. were studied with waveform analysis.

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A Study of Displacement Amplification Factors Considering Hysteretic Behavior of Structural Systems and Earthquake Characteristics (비탄성 이력응답 및 지진특성을 반영한 변위증폭계수에 관한 연구)

  • Song, Jong-Keol;Kim, Hark-Soo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.777-782
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    • 2007
  • Displacement amplification factor can be used to estimate inelastic displacement demands from elastic displacement demands, The simple formula for displacement amplification factor considering hysteretic behavior of structural system and earthquake characteristics is proposed. And the effects of several parameters such as displacement ductility, strain hardening ratio, period, characteristics of earthquakes and hysteretic models for the displacement amplification factor are evaluated. Accuracy of the proposed formula is evaluated by comparing the displacement amplification factors estimated by existing and proposed formula with those calculated from inelastic time history analysis. The displacement amplification factors by proposed formulas provide a good agreement with those calculated by inelastic time history analysis.

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Inelastic Time History Analysis of a 5-Story Reinforced Concrete IMRF (5층 철근콘크리트 중간모멘트골조의 비탄성 시간이력해석)

  • Kang, Suk Bong;Lim, Byeong Jin
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.6
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    • pp.13-20
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    • 2012
  • In this study, 5-story structures were designed in accordance with KBC2009 for inelastic time history analysis of RC IMRF. Bending moment-curvature relationship for beam and column was identified with fiber model and bending moment-rotation relationship for beam-column joint was calculated with simple and unified joint shear behavior model and moment equilibrium relationship for the joint. The hysteretic behavior was simulated with three-parameter model suggested in IDARC program. The analytical results showed that the inelastic shear behavior of the joint could be neglected in the structural design for seismic design category C but the structure of category D did not satisfy the criteria of FEMA 356 for collapse prevention performance level.

Application of Response Spectrum Analysis Method for the Estimation of the Vertical Vibration in Structures (구조물의 연직진동해석을 위한 응답 스펙트럼 해석법의 활용)

  • 이동근
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.12-19
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    • 1998
  • Response spectrum analysis method is widely used for seismic analysis of building structure. Analysis of structural vibration for equipment, machine and moving loads are executed by time history analysis. This method is very complex, difficult and tedious. In this study, maximum response of structure for this case are simply and fast. calculated by mode shape and response spectrum for excitation. At first, Response spectrum and time history analysis for some earthquake is carried and investigate the error of maximum displacement response for R. S. A. Secondly, The process for response spectrum analysis in excitation are calculated, and maximum model response are combined by CQC (Complete Quadratic Combination) methods. Finally, Combining maximum displacement response is compared with one of time history analysis.

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