• Title/Summary/Keyword: dynamic time-history analysis

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Application of Dynamic Reliability Model to Analysis of Armor Stability of Rouble-Mound Breakwaters (경사제 피복재의 안정성 해석에 대한 동적 신뢰성 모형의 적용)

  • Kim, Sung-Ho;Lee, Cheol-Eung
    • Journal of Industrial Technology
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    • v.24 no.A
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    • pp.215-226
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    • 2004
  • A dynamic reliability model which can take into account the time history of loading sequences may be applied to the analyses of the hydraulic stability of armor units on rubble-mound breakwaters. All the parameters related to the stability of structures have been considered to be constants in the deterministic model until now. Thus, it is impossible to study the effects of some uncertainties of the related random variables on the stability of structures. In this paper, the dynamic reliability model can be developed by POT(Peak Over Threshold) method in order to take into account the time history of loading sequences and to investigate the temporal behaviors of stability of structure with its loading history. Finally, it is confirmed that the results of dynamic reliability model agree with straight- forwardly those of AFDA(Approximate Full Distribution Approach) of the static reliability model for the same input conditions. In addition, the temporal behaviors of probability of failure can be studied by the dynamic reliability model developed to analyze the hydraulic stability of armor units on rubble-mound breakwaters. Therefore, the present results may be useful for the management of repair and maintenance over the whole life cycle of structure.

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A Fundamental Study for Time History Modeling of Fluid Impact Pressure (유체 충격압력 시계열의 모델링에 관한 기초 연구)

  • Nho, In-Sik;Lee, Jae-Man;Yeom, Cheol-Woong
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.2
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    • pp.242-247
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    • 2010
  • To consider effects of essential parameters of water impact pressure on dynamic structural responses of bow bottom structures, a parametric study for a ship bottom panel is carried out. The idealized pressure time history models were assumed by triangular and rectangular shapes in time domain. The main loading parameters are duration time and peak pressure value maintaining the same impulse value. The structural models for local bottom stiffened panels of a container ship are analysed. The natural frequency analysis and transient dynamic response analysis are performed using MSC/NASTRAN. Added mass effects of contacting water are considered and the pressure distributions are assumed to be uniform in the whole water contacting surface. The effects of loading parameters on the structural responses, especially maximum displacements, are considered. Besides the peak pressure value, effects of duration time correlated with natural frequencies are thought to be the important parameters.

Optimization of a vehicle component under dynamic fatigue (동적 피로를 고려한 자동차 부품의 최적설계)

  • 이정준;주병현;이병채
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.898-901
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    • 2004
  • Generally, in case the natural frequency of vehicle components is larger than the reversing frequency of load history, we can obtain the analysis results with small errors. But in case of having the low natural frequency, we must avoidably carry out the dynamic analysis, and it requires much time and storage. Specially executing the fatigue analysis for vehicle components requires more time. To this end, it is not easy that we accomplish the optimization considering fatigue for the vehicle component based on the dynamic analysis. In this research we introduce an efficient method which performs the fatigue analysis based on the dynamic analysis. Finally as making the response surface we optimize the vehicle component under dynamic fatigue.

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A Study on Computational Method for Fatigue Life Prediction of Vehicle Structures (차체 구조물의 피로수명 예측을 위한 컴퓨터 시뮬레이션 방법에 관한 연구)

  • Lee, Sang-Beom;Park, Tae-Won;Park, Jong-Sung;Lee, Sun-Byung;Yim, Hong-Jae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1883-1888
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    • 2000
  • In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

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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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    • 2001.04a
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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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Dynamic Experiment to Evaluate Response Characteristics of High-Rise Buildings on Period Characteristics of Seismic Waves (지진파 주기특성에 따른 고층건축물의 응답특성 평가를 위한 동적실험)

  • Oh, Sang-Hoon;Kim, Ju-Chan
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.10
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    • pp.127-133
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    • 2019
  • Damage to high-rise buildings caused by earthquakes is less frequency due to small distribution of high-rise buildings and low transmissibility of seismic motion to high-rise buildings. However, demand for high-rise buildings is increasing for development of construction technology and efficient land use. In addition, if high-rise buildings are constructed on soft ground such as landfill, transmissibility of seismic motion due to long-periodization of seismic waves is likely to increase. Thus, with development of technology, buildings are required to expand range of seismic design such as safety for long-period seismic waves. Therefore, in this study, dynamic experiments were performed to evaluate response characteristics of high-rise buildings according to period characteristics of seismicwaves and time history analysis was performed to verify them.

Application of Response Spectrum Method for Analysis of a Floor System Subjected to Dynamic Loads on Multiple Locations (복수 절점에 가진되는 건물 바닥판의 해석을 위한 응답스펙트럼 해석법의 응용)

  • 김태호;이동근
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.1
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    • pp.21-32
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    • 2002
  • In general, the response spectrum analysis method (R.S.A) is widely used for seismic analysis of building structure. But, it is not common to apply R.S.A for the analysis of structural vibration caused by dynamic loads of equipments, machines and moving leads, etc. The time history analysis method(T.H.A) for the vibration analysis, compared with R.S.A, is very complex, difficult and time consuming. So the application of R.S.A, that is convenient to calculate maximum responses for structural vibration, is proposed in this study. At first, the procedure for the application of the R.S.A to calculate of the maximum vibration response induced by dynamic load applied on the single point is described. And then, the process, which can save the time and the memory for calculation of the maximum vibration response induced by dynamic loads on the multi-point is proposed, and the maximum structural response caused by moving loads are obtained. Lastly, the accuracy of the proposed method is verified by comparing the results of R.S.A to T.H.A for some example models.

Dynamic analysis of a laminated composite beam under harmonic load

  • Akbas, S.D.
    • Coupled systems mechanics
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    • v.9 no.6
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    • pp.563-573
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    • 2020
  • Dynamic responses of a laminated composite cantilever beam under a harmonic are investigated in this study. The governing equations of problem are derived by using the Lagrange procedure. The Timoshenko beam theory is considered and the Ritz method is implemented in the solution of the problem. The algebraic polynomials are used with the trivial functions for the Ritz method. In the solution of dynamic problem, the Newmark average acceleration method is used in the time history. In the numerical examples, the effects of load parameter, the fiber orientation angles and stacking sequence of laminas on the dynamic responses of the laminated beam are investigated.

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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    • 2005.04a
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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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Effects of Material Nonlinearity on Seismic Responses of Multistoried Buildings with Shear Walls and Bracing Systems

  • Islam, Md. Rajibul;Chakraborty, Sudipta;Kim, Dookie
    • Architectural research
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    • v.24 no.3
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    • pp.75-84
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    • 2022
  • Scads of earthquake-resistant systems are being invented around the globe to ensure structural resistance against the lateral forces induced by earthquake loadings considering structural safety, efficiency, and economic aspects. Shear wall and Bracing systems are proved to be two of the most viable solutions for seismic strengthening of structures. In the present study, three numerical models of a G+10 storied building are developed in commercial building analysis software considering shear wall and bracing systems for earthquake resistance. Material nonlinearity is introduced by using plastic hinges. Analyses are performed utilizing two dynamic methods: Response Spectrum analysis and nonlinear Time-history analysis using Kobe and Loma Prieta earthquake data and results are compared to observe the nonlinear behavior of structures. The outcomes exposed that a significant increase in the seismic responses occurs due to the nonlinearity in the building systems. It was also found that building with shear wall exhibits maximum resistance and minimum nonlinearity when subjected to dynamic loadings.