• 제목/요약/키워드: Structural Assessment

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원자로냉각재펌프 맥동에 대한 APR1400 원자로내부구조물의 진동 및 응력 해석 (Vibration and Stress Analysis for Reactor Vessel Internals of Advanced Power Reactor 1400 by Pulsation of Reactor Coolant Pump)

  • 김규형;고도영;김성환
    • 한국소음진동공학회논문집
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    • 제21권12호
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    • pp.1098-1103
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    • 2011
  • The structural integrity of APR1400 reactor vessel internals has been being assessed referring the US Nuclear Regulatory Commission regulatory guide 1.20, comprehensive vibration assessment program. The program is composed of a vibration and stress analysis, a vibration and stress measurement, and an inspection. This paper covers the vibration and stress analysis on the reactor vessel internals by the pulsation of reactor coolant pump. 3-dimensional models to calculate the hydraulic loads and structural responses were built and the pressure distributions and the structural responses were predicted using ANSYS. This paper presents that APR1400 reactor vessel internals have enough structural integrity against the pulsation of reactor coolant pump as the peak stress of the reactor vessel internals is much lower than the acceptance limit.

Efficient Monte Carlo simulation procedures in structural uncertainty and reliability analysis - recent advances

  • Schueller, G.I.
    • Structural Engineering and Mechanics
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    • 제32권1호
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    • pp.1-20
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    • 2009
  • The present contribution addresses uncertainty quantification and uncertainty propagation in structural mechanics using stochastic analysis. Presently available procedures to describe uncertainties in load and resistance within a suitable mathematical framework are shortly addressed. Monte Carlo methods are proposed for studying the variability in the structural properties and for their propagation to the response. The general applicability and versatility of Monte Carlo Simulation is demonstrated in the context with computational models that have been developed for deterministic structural analysis. After discussing Direct Monte Carlo Simulation for the assessment of the response variability, some recently developed advanced Monte Carlo methods applied for reliability assessment are described, such as Importance Sampling for linear uncertain structures subjected to Gaussian loading, Line Sampling in linear dynamics and Subset simulation. The numerical example demonstrates the applicability of Line Sampling to general linear uncertain FE systems under Gaussian distributed excitation.

Seismic assessment of steel structures through a cumulative damage

  • Perera, R.;Gomez, S.;Alarcon, E.
    • Steel and Composite Structures
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    • 제1권3호
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    • pp.283-294
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    • 2001
  • In the present work a constitutive model is developed which permits the assessment of the structural performance through a criterion based on cumulative damage. For it, a damage index is defined and is evaluated through the application of the Miner's rule in low-cycle fatigue. However, the damage index is not considered as a posteriori variable since is incorporated explicitly as an internal variable in the constitutive equations which produces a direct coupling between the damage and the structural mechanical behaviour allowing the possibility of considering as a whole different coupled phenomena. For the elaboration of this damage model, the concepts of the mechanics of continuum medium are applied on lumped dissipative models in order to obtain a coupled simplified model. As a result an elastoplastic model coupled with damage and fatigue damage is obtained.

Seismic Assessment and Performance of Nonstructural Components Affected by Structural Modeling

  • Hur, Jieun;Althoff, Eric;Sezen, Halil;Denning, Richard;Aldemir, Tunc
    • Nuclear Engineering and Technology
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    • 제49권2호
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    • pp.387-394
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    • 2017
  • Seismic probabilistic risk assessment (SPRA) requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

APR1400 원자로 내부배럴집합체 상부판 구조응답해석 (Structural Response Analysis on Inner Barrel Assembly Top Plate of APR1400 Reactor Vessel)

  • 김규형;고도영;김성환
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.907-910
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    • 2012
  • Since the inner barrel assembly of the Advanced Power Reactor 1400 reactor vessel is a new design feature introduced instead of CEA(control element assembly) shroud assembly, the inner barrel assembly can be a significant object of structural integrity assessment. This paper covers the structural responses of top plate, which is a component of the inner barrel assembly, against the deterministic hydraulic load induced by pump pulsation and the random hydraulic load induced by turbulence of coolant. The top plate responds to the deterministic hydraulic load more than to the random hydraulic load and shows enough structural integrity. The results of this paper will be important basis for the selection of instruments and measurement location.

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LNG선 단열시스템의 슬로싱 충격하중에서의 국부확대해석 (Local Zooming Analysis of LNGC CCS under Sloshing Impact Loading)

  • 이상갑;;조헌일;김진경;안지웅
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2011년도 정기 학술대회
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    • pp.544-551
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    • 2011
  • As the cargo tank size and configuration of Liquefied Natural Gas carriers(LNGC) grows in response to the global increase in demands for LNG and the necessities of its economical transportation, impact loading from sloshing may become one of the most important factors in the structural safety of LNG Cargo Containment Systems(CCS). The objective of this study is to demonstrate the procedure of the structural safety assessment of MARK III membrane type CCS under sloshing impact loading using local zooming analysis technique of LS-DYNA code.

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