• Title/Summary/Keyword: Time-History analysis

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Seismic performance evaluation of coupled core walls with concrete and steel coupling beams

  • Fortney, Patrick J.;Shahrooz, Bahram M.;Rassati, Gian A.
    • Steel and Composite Structures
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    • v.7 no.4
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    • pp.279-301
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    • 2007
  • When coupling beams are proportioned appropriately in coupled core wall (CCW) systems, the input energy from ground motions is dissipated primarily through inelastic deformations in plastic hinge regions at the ends of the coupling beams. It is desirable that the plastic hinges form at the beam ends while the base wall piers remain elastic. The strength and stiffness of the coupling beams are, therefore, crucial if the desired global behavior of the CCW system is to be achieved. This paper presents the results of nonlinear response history analysis of two 20-story CCW buildings. Both buildings have the same geometric dimensions, and the components of the buildings are designed based on the equivalent lateral force procedure. However, one building is fitted with steel coupling beams while the other is fitted with diagonally reinforced concrete coupling beams. The force-deflection relationships of both beams are based on experimental data, while the moment-curvature and axial load-moment relationships of the wall piers are analytically generated from cross-sectional fiber analyses. Using the aforementioned beam and wall properties, nonlinear response history analyses are performed. Superiority of the steel coupling beams is demonstrated through detailed evaluations of local and global responses computed for a number of recorded and artificially generated ground motions.

Evaluation of Ergonomic Performance of Medical Smart Insoles

  • Yi, Jae-Hoon;Lee, Jin-Wook;Seo, Dong-Kwon
    • Physical Therapy Rehabilitation Science
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    • v.11 no.2
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    • pp.215-223
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    • 2022
  • Objective: This study was to resolve the limitations of the experimental environment and to solve the shortcomings of the method of measuring human gait characteristics using optical measuring instruments. Design: A cross-sectional study. Methods: Fifteen healthy adults without a history of orthopedic surgery on the lower extremities for the past 6 months were participated. They were analyzed gait variables using the smart guide and the 3D image analysis at the same time, and their results were compared. Visual-3D was used to calculate the analysis variables. Results: The reliability and validity of the data according to the two measuring instruments were found to be very high; gait speed(0.85), cycle time(0.99), stride time of both feet(0.98, 0.97) stride legnth of both feet(0.86, 0.88) stride per minute of both feet(0.99, 0.96), foot speed of both feet(0.90, 0.91), step time of both feet(0.77, 0.71), step per minute(0.72, 0.74), stance time of both feet(0.96, 0.97), swing time of both feet(0.93, 0.79), double step time(0.81), initial double step time(0.84) and terminal step time(0.76). Conclusions: In the case of the smart insole, which measures human gait variables using the pressure sensor and inertial sensor inserted in the insole, the reliability and validity of the measured data were found to be very high. It can be used as a device to replace 3D image analysis when measuring pathological gait.

Seismic Analysis of Building Structures with Ambiguous Modal Direction (모드의 방향이 불분명한 건축구조물의 지진해석)

  • 김태호;이동근;김대곤
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.513-520
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    • 2002
  • This study is for seismic analysis of building structures with ambiguous modal direction This case is revealed symmetrical building structure or the structure that isn't coincided building axis with physical axis. Seismic analysis-time history analysis, response spectrum analysis and lateral force procedure-is carried out. It is concluded that analysis method for the structure with ambiguous modal direction don't suitable for lateral force procedure. It is recommended to use the CQC method for combining modal responses to the individual components and the SRSS rule for combining responses to the two horizontal components are of nearly equal intensities.

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Analysis of change characteristics through estimating the limit rainfall by period (기간별 한계강우량 산정을 통한 변화 특성 분석)

  • Hwang, Jeong Geun;Cho, Jae Woong;Kang, Ho Seon;Lee, Han Seung;Moon, Hye Jin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.99-99
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    • 2020
  • The frequency and scale of domestic flood damage continues to increase, but the criteria for responding to flood damage have not been established. To this end, research is underway to estimate the amount of rainfall in each region so that it can be used to respond to flood damage. The limit rainfall is defined as the cumulative maximum rainfall for each duration that causes flooding, and this research purpose to improve the threshold rainfall by estimating the damage based on the damage history in units of 5 years and analyzing changes over time. The limit rainfall based on the damage history was estimated by using the NDMS past damage history of the Ministry of the Interior and Safety and the rainfall minutes data of AWS and ASOS. The period for estimating the limit rainfall is 2013 ~ 2017, 2015 ~ 2019, and the limit rainfall is estimated by analyzing the relationship between the flood damage history and the rainfall event in each period. Considering changes in watershed characteristics and disaster prevention performance, the data were compared using 5-year data. As a result of the analysis, the limit rainfall based on the damage history could be estimated for less than about 10.0% of the administrative dongs nationwide. As a result of comparing the limit rainfall by period, it was confirmed that the area where the limit rainfall has increased or decreased This was analyzed as a change due to rainfall events or urbanization, and it is judged that it will be possible to improve the risk criteria of flooding.

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Fragility Curve Evaluation of Reinforced Concrete Shear Wall Structures according to Various Nonlinear Seismic Analysis Methods (다양한 비선형지진해석방법에 따른 철근콘크리트 전단벽 구조물의 취약도곡선 평가)

  • Jang, Dong-Hui;Song, Jong-Keol;Kang, Sung-Lib;Park, Chang-Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.15 no.4
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    • pp.1-12
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    • 2011
  • Seismic fragility analysis has been developed to evaluate the seismic performance of existing nuclear power plants, but now its applicability has been extended to buildings and bridges. In general, the seismic fragility curves are evaluated from the nonlinear time-history analysis (THA) using many earthquake ground motions. Seismic fragility analysis using the nonlinear THA requires a time consuming process of structural modeling and analysis. To overcome this shortcoming of the nonlinear THA, simplified methods such as the displacement coefficient method (DCM) and the capacity spectrum method (CSM) are used for the seismic fragility analysis. In order to evaluate the accuracy of the seismic fragility curve calculated by the DCM and the CSM, the seismic fragility curves of a reinforced concrete shear wall structure calculated by the DCM and CSM are compared with those calculated by the nonlinear THA. In order to construct a numerical fragility curve, 190 artificially generated ground motions corresponding to the design spectrum and the methodology proposed by Shinozuka et al. are used.

A Hurst Exponent as the Measure for a Sinusoid Pattern Recognition (Sinusoid 패턴 인식을 위한 측도로서의 허스트 지수)

  • 차경준;황선호
    • Journal for History of Mathematics
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    • v.17 no.2
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    • pp.85-96
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    • 2004
  • The Resealed range statistical analysis and Hurst exponent which are standard methods to test the chaotic model are used to examine sinusoid pattern. We notice that the Hurst exponent can be used as a measure to examine the time series data that show semi-cyclic trend with noise.

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A Study on the Characteristics of Building Composition of Zen Buddhist Temples in Northern Song Dynasty (북송대 선종사원의 가람 구성 특징에 관한 연구)

  • Han, Ji-Man
    • Journal of architectural history
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    • v.25 no.3
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    • pp.47-62
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    • 2016
  • The purpose of this study is to clarify the characteristics of Zen Buddhist temple's building composition of the Northern Song dynasty, through the analysis of literature historical material, such as Seonwon chenggyu(禪苑淸規), Cham cheontae odaesan gi(參天台五臺山記) and so on. The building composition method of Zen Buddhist temple in Northern Song dynasty, which grasped from the Seonwon chenggyu, reflects the actual situation of the temples in that time. And it was ascertained that, the Zen Buddhist temple's building composition of the Northern Song dynasty was basically same to that of Southern Song dynasty. And the comparative analysis was attempted between Zen Buddhist temples and that of other Buddhism sect described in Cham cheontae odaesan gi. From this analysis, the common features as Buddhism temple and the characteristics of building composition as Zen Buddhist temple was clarified.

The bridge behavior analysis by means of time history analysis according to the railway velocity (시간이력해석을 이용한 철도 주행속도에 따른 교량의 거동분석)

  • Lee Jong-seon;Lee Jae-Yeol;Hwang Nag-yeon;Kim Kyoung-Nam;Jung Kyoung-Sup
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.368-375
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    • 2003
  • Now a days, the fabrication and election skills have improved in Korea. Due to taking the vertical clearance and a point of beauty, the election of the suspension and the cable-stayed bridges whose span length can be lengthened have been increased. Accordingly, there are link areas between the bridges by cables and other bridges. These dynamic behaviors are different from others. When the vehicles and trains run on the link area, the member force and the fatigue behavior which are occurred to the structure have different values depend on the velocity. On this paper, we analyze the bridge behavior by means of the tine history analysis depend on to velocity, the number of vehicles, single and double way.

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A Study on Evaluation of Floor Response Spectrum for Seismic Design of Non-Structural Components (비구조요소의 내진 설계를 위한 기존 층응답스펙트럼의 평가)

  • Choi, Kyung Suk;Yi, Waon Ho;Yang, Won-Jik;Kim, Hyung Joon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.6
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    • pp.279-291
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    • 2013
  • The seismic damage of non-structural components, such as communication facilities, causes direct economic losses as well as indirect losses which result from social chaos occurring with downtime of communication and financial management network systems. The current Korean seismic code, KBC2009, prescribes the design criteria and requirements of non-structural components based on their elastic response. However, it is difficult for KBC to reflect the dynamic characteristics of structures where non-structural components exist. In this study, both linear and nonlinear time history analyses of structures with various analysis parameters were carried out and floor acceleration spectra obtained from analyses were compared with both ground acceleration spectra used for input records of the analyses and the design floor acceleration spectrum proposed by National Radio Research Agency. Also, this study investigates to find out the influence of structural dynamic characteristics on the floor acceleration spectra. The analysis results show that the acceleration amplification is observed due to the resonance phenomenon and such amplification increases with the increase of building heights and with the decrease of structure's energy dissipation capacities.

Analysis of the Degree of Fatigue Damage in Truss Railway Bridge by Actual Stress and Simulation (실측응력 및 시뮬레이션에 의한 트러스 철도교의 피로피해도 분석)

  • Jung, Young-Hwa;Kim, Ik-Gyeom;Kim, Ji-Hun;Kim, eun-sung
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.149-158
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    • 2000
  • After measuring actual stress by two measurements(Dynamic Strain Meter, Histogram Recorder) on truss rail road bridge, we could perform time history analysis by 3-D beam element method on modelling bridge. And then, after analyzing bridge structure in static by 3-D modelling, we estimated degree of fatigue damage in main member, secondary member of tie zone, cutting area of base metal cross section for confirming the result. In case that the simulated stress is carried out on modeling bridge, most of those simulation mainly is performed by main members. But in real bridge fatigue damage problems generally caused by junctions, connections, joints in which especially local stress is activated. Therefore, in this paper actual stress on critical area was estimated through the analysis result by simulation. With this study, we can estimate the degree of fatigue damage from a safety point of view and comparative accuracy.

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