• Title/Summary/Keyword: Time history

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Seismic Response Analysis of a Isolated Lumped-Mass Beam Model (면진된 집중질량 보 모델의 지진응답해석)

  • 이재한;구경회
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.561-568
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    • 2001
  • For obtaining the time history nodal responses of reactor building, a lumped-mass beam model composed of two sticks for the reactor building and the reactor support structure is developed. The time history responses for the non-isolated and isolated reactor buildings are calculated under an artificial time history, generated using the seismic spectrum curve of US NRC RG1.60. The analysis results show that the horizontal accelerations of the isolated building are dramatically decreased to one-tenths of the non-isolated one, but the vertical responses are increased by about 40%.

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Calculation of Dynamic Stress-Time History for a Vehicle Using Flexible Body Dynamics Model (유연체 동력학 모델을 이용한 차량의 동응력-시간선도 계산)

  • Park, Chan-Jong;Yim, Hong-Jae;Park, Tae-Won
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.702-707
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    • 2000
  • Under the rapid change of a new vehicle model, it is necessary to develop a durability analysis technique using computer simulation. In order to do this. reliable dynamic stress-time history for the vehicle components must be calculated on various road conditions. In this paper, a full vehicle simulation model which is composed of flexible frame and chassis components is proposed and verified its reliability from the comparison with field test data. Finally, dynamic stress-time history on the rear chassis components is predicted with hybrid and modal superposition method.

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The soil effect on the seismic behaviour of reinforced concrete buildings

  • Yon, Burak;Calayir, Yusuf
    • Earthquakes and Structures
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    • v.8 no.1
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    • pp.133-152
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    • 2015
  • This paper investigates the soil effect on seismic behaviour of reinforced concrete (RC) buildings by using the spread plastic hinge model which includes material and geometric nonlinearity of the structural members. Therefore, typical reinforced concrete frame buildings are selected and nonlinear dynamic time history analyses and pushover analyses are performed. Three earthquake acceleration records are selected for nonlinear dynamic time history analyses. These records are adjusted to be compatible with the design spectrum defined in Turkish Seismic Code. Interstory drifts and damages of selected buildings are compared according to local soil classes. Also, capacity curves of these buildings are compared with maximum responses obtained from nonlinear dynamic time history analyses. The results show that, soil class influences the seismic behaviour of reinforced concrete buildings, significantly.

A Technique to Link Bug and Commit Report based on Commit History (커밋 히스토리에 기반한 버그 및 커밋 연결 기법)

  • Chae, Youngjae;Lee, Eunjoo
    • KIISE Transactions on Computing Practices
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    • v.22 no.5
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    • pp.235-239
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    • 2016
  • 'Commit-bug link', the link between commit history and bug reports, is used for software maintenance and defect prediction in bug tracking systems. Previous studies have shown that the links are automatically detected based on text similarity, time interval, and keyword. Existing approaches depend on the quality of commit history and could thus miss several links. In this paper, we proposed a technique to link commit and bug report using not only messages of commit history, but also the similarity of files in the commit history coupled with bug reports. The experimental results demonstrated the applicability of the suggested approach.

Time-History Analysis on Structure Dynamic Response for the SDOF System of Ground Vibration by the Newmark $\beta$ method (Newmark $\beta$ 방법에 의한 지반진동의 단자유도계 구조물 동적응답 시간이력 해석)

  • Kim, Jong-In;Kang, Seong-Seung
    • Tunnel and Underground Space
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    • v.20 no.4
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    • pp.292-298
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    • 2010
  • The purpose of this study is to evaluate an effect of ground vibration caused by blasting on the concrete brick structure. For the purpose, dynamic response time-history of the structure assumed single degree of freedom (SDOF) system and vibration time-history directly measured from the structure were examined, using Newmark $\beta$ method based on data measured at ground. The time-history was interpreted from the measured data of ground and structure in single hole blasting. Vibration magnitude between ground vibration and structure in single hole blasting and 20 ms interval blasting was about three times and was shown larger vibration on the structure. By time-history analysis of structure dynamic response, the value was almost the same one with the data measured from the structure. It indicates that the vibration characteristics of structures may be predicted on the basis of the ground vibration data measured from the sub-ground of structure.

Generation of Artificial Time History Earthquake Record Family using the Least Squares Fitting Method (최소오차 최적합화 방법에 의한 인공 시간이력 지진기록군의 생성)

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.5
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    • pp.31-38
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    • 2008
  • Recently the necessity of time history analyses is increasing for the seismic analyses of a structure, and the seismic design provisions of IBC2003, ASCE and KBC2005 require the use of a minimum of seven earthquake records for the time history analyses. Earthquake records for the time history analyses could be selected from the database of the field-measured earthquake records having similar site conditions with the designed site, or from simulated sites satisfying the design spectrum. However, in this study seven earthquake records were generated using 50 earthquake records, classified as records measured at the rock, in the database of the Pacific Earthquake Research Center (PEER). Seven earthquake records were first selected by the least squares fitting method comparing the scaling factored response spectra with the specified design spectrum, and a family of seven artificial time history earthquake records was ultimately generated by multiplying scaling factors, which were calculated by the least squares fitting method and the SRSS averaging method, to the corresponding selected earthquake records.

Response of Base Isolation System Subjected to Spectrum Matched Input Ground Motions (스펙트럼 적합 입력지반운동에 의한 면진구조의 응답 특성)

  • Kim, Jung Han;Kim, Min Kyu;Choi, In-Kil
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.2
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    • pp.89-95
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    • 2013
  • Structures in a nuclear power system are designed to be elastic even under an earthquake excitation. However a structural component such as an isolator shows inelastic behavior inherently. For the seismic assessment of nonlinear structures, response history analysis should be performed. In this study, the response of base isolation system was analyzed by response history analysis for the seismic performance assessment. Firstly, several seismic assessment criteria for a nuclear power plant structure were reviewed for the nonlinear response history analysis. Based on these criteria, the spectrum matched ground motion generation method modifying a seed earthquake ground motion time history was adjusted. Using these spectrum matched accelerograms, the distribution of displacement responses of the simplified base isolation system was evaluated. The resulting seismic responses excited by the modified ground motion time histories and the synthesized time history generated by stochastic approach were compared. And the response analysis of the base isolation system considering the different intensities in each orthogonal direction was performed.

Changes in the Archive construction environment of Local architectural history research resources in Korea (국내 지역건축역사 연구자원의 아카이브 구축 환경 변화)

  • Kim, Jeong-Hee;Han, Dong-Soo
    • Journal of architectural history
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    • v.32 no.1
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    • pp.73-88
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    • 2023
  • Recently, local studies looking at the 'local(region) as a whole' are gradually increasing. The study of local architectural history is important in that it provides specific information that encompasses the local and the entire and clues to three-dimensionalize the time and space in the local. To infer the 'presentness' of each era, reliable data in various fields are needed. Recently, as many databases (DB) and archives, from the 'National Archives of Korea' to other local archives, have been established and publicized, research resources in the local are growing rapidly in quantity and quality. Nevertheless, it is difficult to comprehensively check the data necessary to study the local architectural history(local architectural history research resources). Against this background, this study confirmed the trend of changes in the archive construction environment and the status and problems of local architectural history research resources in places that currently disclose local history research resources among generalized web-archives. Next, the relationship between the actual research on local architectural history was confirmed through the analysis of existing studies and the data used for Jeju. As a result, local studies, local archives, and local architectural history research agree with recent changes in local research trends, and the degree of archival construction has reached the same level as the available research resources except core data in local architectural history research. However, there is a problem that the density of information that can be used is low because the local architectural history research resources that can be obtained are fragmented because there are no archives and construction entities specialized in local architecture. As each archive has entered the stabilization and upgrading stage, the construction of new archives needs to be reconsidered, but it is time to find a detailed way to link related information quickly and accurately, such as private records, to reduce the gap in information needed in terms of research on local architecture and architecture history.

Computing input energy response of MDOF systems to actual ground motions based on modal contributions

  • Ucar, Taner
    • Earthquakes and Structures
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    • v.18 no.2
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    • pp.263-273
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    • 2020
  • The use of energy concepts in seismic analysis and design of structures requires the understanding of the input energy response of multi-degree-of-freedom (MDOF) systems subjected to strong ground motions. For design purposes and non-time consuming analysis, however, it would be beneficial to associate the input energy response of MDOF systems with those of single-degree-of-freedom (SDOF) systems. In this paper, the theoretical formulation of energy input to MDOF systems is developed on the basis that only a particular portion of the total mass distributed among floor levels is effective in the nth-mode response. The input energy response histories of several reinforced concrete frames subjected to a set of eleven horizontal acceleration histories selected from actual recorded events and scaled in time domain are obtained. The contribution of the fundamental mode to the total input energy response of MDOF frames is demonstrated both graphically and numerically. The input energy of the fundamental mode is found to be a good indicator of the total energy input to two-dimensional regular MDOF structures. The numerical results computed by the proposed formulation are verified with relative input energy time histories directly computed from linear time history analysis. Finally, the elastic input energies are compared with those computed from time history analysis of nonlinear MDOF systems.

Stress History of a Bridge Estimated from Statistical Analysis of Traffic Bow (교통류의 통계적 해석으로부터 추정한 교량의 응력이력)

  • Yong, Hwan Sun;Choi, Kang Hee;Choi, Sung Kweon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.1
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    • pp.1-10
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    • 1989
  • The stress history of a bridge is different depending on the characteristic of traffic flow. Because the flow is varied with vehicle type, weight and headway time etc., statistical analysis in bridges is necessary to estimate the history by traffic flow. By applying the statistical analyses in fracture mechanics, the remaining service life of the structure can be estimated. In this paper, 1)the statistical analysis of vehicle type, weight and headway time etc. to analysis randomness of traffic flow, 2)measuring and analysis of stress history of a real bridge, 3)reappearance of stress history by Monte-Carlo Simulation using constitution ratio of vehicle type, weight and headway time as probabilitic variable, 4)comparision of the calculated and modelled stress history, 5)calculation of reduction factor, 6)comparision of frequency of stress range depending on span length etc. were performed. From the results, the basic modelled stress history which is necessary for the method of estimation of the remaining service life of the structure could be suggested.

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