• Title/Summary/Keyword: Spectrum response

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Evaluation of Response Spectrum Shape Effect on Seismic Fragility of NPP Component (스펙트럼 형상이 원전 기기 지진취약도에 미치는 영향 평가)

  • 최인길;서정문;전영선;이종림
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.4
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    • pp.23-30
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    • 2003
  • The result of recent seismic hazard analysis indicates that the ground motion response spectra for Korean nuclear power plant site have relatively large frequency acceleration contents. In the ordinary seismic fragility analysis of nuclear power plant structures and equipments, the safety margin of design ground response spectrum is directly used as a response spectrum shape factor. The effects of input response spectrum shape on the floor response spectrum were investigated by performing the direct generation of floor response spectrum from the ground response spectrum. The safety margin included in the design ground response spectrum should be considered as a floor response spectrum shape factor for the seismic fragility analysis of the equipments located in a building.

Seismic Fragility Analysis of NPP Components for High Frequency Ground Motions (고진동수 지진동에 대한 원전 기기의 지진취약도 분석)

  • 최인길;서정문;전영선
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.110-117
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    • 2003
  • The result of recent seismic hazard analysis indicates that the ground motion response spectra for Korean nuclear power plant site have relatively large high frequency acceleration contents. In the ordinary seismic fragility analysis of nuclear power plant structures and equipments, the safety margin of design ground response spectrum is directly used as a response spectrum shape factor. The effects of input response spectrum shape on the floor response spectrum were investigated by performing the direct generation of floor response spectrum from the ground response spectrum. The safety margin included in the design ground response spectrum should be considered as a floor response spectrum shape factor for the seismic fragility analysis of the equipments located in a building.

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A response spectrum method for seismic response analysis of structures under multi-support excitations

  • Li, Jian-Hua;Li, Jie
    • Structural Engineering and Mechanics
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    • v.21 no.3
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    • pp.255-273
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    • 2005
  • Based on the random vibration theory, a response spectrum method is developed for seismic response analysis of linear, multi-degree-of-freedom structures under multi-support excitations is developed. Various response quantities, including the mean and variance of the peak response, the response mean frequency, are obtained from proposed combination rules in terms of the mean response spectrum. This method makes it possible to apply the response spectrum to the seismic reliability analysis of structures subjected to multi-support excitations. Considering that the tedious numerical integration is required to compute the spectral parameters and correlation coefficients in above combination rules, this paper further offers simplified procedures for their computation, which enhance dramatically the computational efficiency of the suggested method. The proposed procedure is demonstrated for tow numerical examples: (1) two-span continuous beam; (2) two-tower cabled-stayed bridge by using Monte Carlo simulation (MC). For this purpose, this paper also presents an approach to simulation of ground motions, which can take into account both mean and variation properties of response spectrum. Computed results based on the response spectrum method are in good agreement with Monte Carlo simulation results. And compared with the MSRS method, a well-developed multi-support response spectrum method, the proposed method has an incomparable computational efficiency.

Development of Neural-Networks-based Model for the Generation of an Earthquake Response Spectrum and a Design Spectrum (지진 응답 스펙트럼과 설계용 응답 스펙트럼 생성을 위한 신경망 모델의 개발)

  • 조빈아;이승창;한상환;이병해
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.447-454
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    • 1998
  • The paper describes the second half of the research for the development of Neural-Networks-based model for the generation of an Artificial earthquake and a Response Spectrum(NNARS). Based on the redefined traditional processes related to the generation of an earthquake acceleration response spectrum and design spectrum, four neural-networks-based models are proposed to substitute the traditional processes. RS_NN tries to directly generate acceleration response spectrum with basic data that are magnitude, epicentral distance, site conditions and focal depth. The test results of RS_NN are not good because of the characteristics of white noise, which is randomly generated. ARS_NN solve this problem by the introduction of the average concept. IARS_NN has a role to inverse the ARS_NN, so that is applied to generate a ground motion accelerogram compatible with the shape of a response spectrum. Additionally, DS_NN directly produces design spectrum with basic data. As these four neural networks are simulated as a step by step, the paper describes the methods to generate a response spectrum and a design spectrum using the neural networks.

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A Comparative Study on Evaluation of Response spectrum accounting for Soil Types (지반 종류별 응답스펙트럼 평가에 대한 비교 연구)

  • 김선우;한상환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.433-438
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    • 2001
  • The response spectrum has been widely used to differentiate the significant characteristics of earthquake ground motion and to evaluate the response of structures under ground shaking. Current design response spectrum is based on Seed, Ugas, and Lysmer's study. (1976) In this study, earthquake ground motion data sets adopted by Seed, Miranda, and Riddell is analyzed regards to soil types. And how earthquake data sets effected the design response spectrum is evaluated using acceleration-displacement response spectrum.

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Study on the Improvement of Response Spectrum Analysis of Pile-supported Wharf with Virtual Fixed Point (가상고정점기법이 적용된 잔교식 구조물의 응답스펙트 럼해석법 개선사항 도출 연구)

  • Yun, Jung Won;Han, Jin Tae
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.6
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    • pp.311-322
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    • 2018
  • As a method of seismic-design for pile-supported wharves, equivalent static analysis, response spectrum analysis, and time history analysis method are applied. Among them, the response spectrum analysis is widely used to obtain the maximum response of a structure. Because the ground is not modeled in the response spectrum analysis of pile-supported wharves, the amplified input ground acceleration should be calculated by ground classification or seismic response analysis. However, it is difficult to calculate the input ground acceleration through ground classification because the pile-supported wharf is build on inclined ground, the methods to calculate the input ground acceleration proposed in the standards are different. Therefore, in this study, the dynamic centrifuge model tests and the response spectrum analysis were carried out to calculate the appropriate input ground acceleration. The pile moment in response spectrum analysis and the dynamic centrifuge model tests were compared. As a result of comparison, it was shown that the response spectrum analysis results using the amplified acceleration in the ground surface were appropriate.

A Study on the Relationship between Response Spectrum and Seismic Fragility Using Single Degree of Freedom System (단자유도 해석모델을 활용한 응답스펙트럼과 지진취약도 곡선과의 관계에 대한 연구)

  • Park, Sangki;Cho, Jeong-rae;Cho, Chang-beck;Lee, JinHyuk;Kim, Dong-Chan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.6
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    • pp.245-252
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    • 2023
  • In general, the design response spectrum in seismic design codes is based on the mean-plus-one-standard deviation response spectrum to secure high safety. In this study, response spectrum analysis was performed using seismic wave records adopted in domestic horizontal design spectrum development studies, while three response spectra were calculated by combining the mean and standard deviation of the spectra. Seismic wave spectral matching generated seismic wave sets matching each response spectrum. Then, seismic fragility was performed by setting three damage levels using a single-degree-of-freedom system. A correlation analysis was performed using a comparative analysis of the change in the response spectrum and the seismic fragility concerning the three response spectra. Finally, in the case of the response spectrum considering the mean and standard deviation, like the design response spectrum, the earthquake load was relatively high, indicating that conservative design or high safety can be secured.

Development of Probabilistic Site Coefficient (확률론적 지진계수 개발)

  • Kwak, Dong-Yeop;Jeong, Chang-Gyun;Park, Du-Hee
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.707-714
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    • 2009
  • The design response spectrum generally used in Korea is decided by the site coefficients determined by deterministic methodology, while it is based on probabilistic seismic hazard analysis. The design response spectrum has to be made using probabilistic method which includes uncertainties of ground motions and ground properties for coincide with probabilistic methodology of seismic hazard analysis. In this study probabilistic site coefficients were developed, which were defined by the results of site response analysis using a set of ground motion that was compatible with present seismic hazard map. The design response spectrum defined by probabilistic seismic coefficients resulted in lower spectrum in long period area and larger spectrum in short period area. Also, the maximum spectral accelerations in site class D and site class E were lower than one in site class C while in the previous design response spectrum the maximum spectral acceleration increased from site class A to E.

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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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    • 1999.04a
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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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