• Title/Summary/Keyword: Probabilistic Analysis

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Probabilistic analysis of gust factors and turbulence intensities of measured tropical cyclones

  • Tianyou Tao;Zao Jin;Hao Wang
    • Wind and Structures
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    • v.38 no.4
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    • pp.309-323
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    • 2024
  • The gust factor and turbulence intensity are two crucial parameters that characterize the properties of turbulence. In tropical cyclones (TCs), these parameters exhibit significant variability, yet there is a lack of established formulas to account for their probabilistic characteristics with consideration of their inherent connection. On this condition, a probabilistic analysis of gust factors and turbulence intensities of TCs is conducted based on fourteen sets of wind data collected at the Sutong Cable-stayed Bridge site. Initially, the turbulence intensities and gust factors of recorded data are computed, followed by an analysis of their probability densities across different ranges categorized by mean wind speed. The Gaussian, lognormal, and generalized extreme value (GEV) distributions are employed to fit the measured probability densities, with subsequent evaluation of their effectiveness. The Gumbel distribution, which is a specific instance of the GEV distribution, has been identified as an optimal choice for probabilistic characterizations of turbulence intensity and gust factor in TCs. The corresponding empirical models are then established through curve fitting. By utilizing the Gumbel distribution as a template, the nexus between the probability density functions of turbulence intensity and gust factor is built, leading to the development of a generalized probabilistic model that statistically describe turbulence intensity and gust factor in TCs. Finally, these empirical models are validated using measured data and compared with suggestions recommended by specifications.

Probabilistic Analysis of Equivalent Uniformly Distributed live toads (등가등분포 적재하중의 확률론적 분석)

  • 김상효;정시현;조형근
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1989.04a
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    • pp.1-4
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    • 1989
  • Since 1960's, structural engineers have recognized that tile inherent random nature of loadings and materials as well as the imperfect structural analysis may be important factors in tile structural safety evaluation. Based on the successful developments of the reliability based structural analysis and design, the design criteria of tile standards are recently developed(or modified) in the light of the probabilistic concepts. To develop the probability-based design criteria for tile domestic buildings, the probabilistic characters of loadings acting on structures should be defined first. In this study, therefore, live load data on apartment buildings have collected and analyzed in a systematic manner, and their probabilistic characteristics have been studied. Based oil the results, the lifetime extreme values are computed and compared with current design loads. More rational design loads are suggested, which are more consistent in the probabilistic concepts.

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Reliability Assessment of Long-Period Cable-Stayed Bridges on Near Fault Earthquake(NFE) (근거리지진에서 장주기사장교의 신뢰성평가)

  • Bang, Myung-Seok
    • Journal of the Korean Society of Safety
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    • v.27 no.1
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    • pp.44-48
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    • 2012
  • The seismic safety of long-period cable-stayed bridges is assessed by probabilistic finite element analysis and reliability analysis under NFE. The structural response of critical members of cable-stayed bridges is evaluated using the developed probabilistic analysis algorithm. In this study, the real earthquake recording(Chi-Chi Earthquake; 1997) was selected as the input NFE earthquake for investigating response characteristics. The probabilistic response and reliability index shows the different aspect comparing the result from FFE earthquake. Therefore, the probabilistic seismic safety assessment on NFE earthquakes should be performed for the exact evaluation of long-period cable-stayed bridges and the earthquake resistant design criteria should be complemented.

Probabilistic Fracture Mechanics Analysis of Reactor Vessel for Pressurized Thermal Shock - The Effect of Residual Stress and Fracture Toughness - (가압열충격에 대한 원자로 용기의 확률론적 파괴역학해석 - 잔류응력 및 파괴인성곡선의 영향 -)

  • Jung, Sung-Gyu;Jin, Tae-Eun;Jhung, Myung-Jo;Choi, Young-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.6
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    • pp.987-996
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    • 2003
  • The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability Is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated.

A Concept of Probabilistic Maintenance Cost Analysis Considering Risk Factors of Aged Multi-Family Housing (노후 공동주택의 위험요인을 고려한 확률적 유지관리비 분석 개념)

  • Park, Moon-Sun;Won, Seo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.246-247
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    • 2019
  • This study was conducted to provide useful information to enable planned repair and cost planning during the operation and maintenance phase of aged multi-family housing. For this purpose, The concept of probabilistic maintenance cost analysis considering the risk factors of the aged multi-family housing is presented in the following six steps. 1. Risk factor investigation and analysis 2. Classification and deriving of maintenance cost 3. Investigation and deriving cost maintenance cost of old apartment house 4. Analysis of expert questionnaire 5. Analysis of Monte -Carlo simulation 6. Probabilistic maintenance cost Deriving the result. This study has limitations that need to be verified by applying actual data.

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Probabilistic Fatigue Life Evaluation for a Car Body Structure (차체 구조물의 확률론적 피로수명 평가 연구)

  • 구병춘;서정원;김재훈
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.150-155
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    • 2002
  • En case of the fatigue life evaluation of rolling stock structures, mainly deterministic fatigue life evaluation has been carried out. But most of the parameters influencing on the fatigue life have a probabilistic distribution such as normal, log-normal, Weibull, etc. Therefore, to take probabilistic factors into fatigue life evaluation, probabilistic methods are being applied to the fatigue life evaluation of rolling stock. In this paper, probabilistic S-N analysis and methods using limit state functions are introduced. And some results of fatigue life evaluation obtained with these methods for rolling stock structures are shown.

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Probabilistic Approach of Stability Analysis for Rock Wedge Failure (확률론적 해석방법을 이용한 쐐기파괴의 안정성 해석)

  • Park, Hyuck-Jin
    • Economic and Environmental Geology
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    • v.33 no.4
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    • pp.295-307
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    • 2000
  • Probabilistic analysis is a powerful method to quantify variability and uncertainty common in engineering geology fields. In rock slope engineering, the uncertainty and variation may be in the form of scatter in orientations and geometries of discontinuities, and also test results. However, in the deterministic analysis, the factor of safety which is used to ensure stability of rock slopes, is based on the fixed representative values for each parameter without a consideration of the scattering in data. For comparison, in the probabilistic analysis, these discontinuity parameters are considered as random variables, and therefore, the reliability and probability theories are utilized to evaluate the possibility of slope failure. Therefore, in the probabilistic analysis, the factor of safety is considered as a random variable and replaced by the probability of failure to measure the level of slope stability. In this study, the stochastic properties of discontinuity parameters are evaluated and the stability of rock slope is analyzed based on the random properties of discontinuity parameters. Then, the results between the deterministic analysis and the probabilistic analysis are compared and the differences between the two analysis methods are explained.

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Probabilistic time-dependent sensitivity analysis of HPC bridge deck exposed to chlorides

  • Ghosh, Pratanu;Konecny, Petr;Lehner, Petr;Tikalsky, Paul J.
    • Computers and Concrete
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    • v.19 no.3
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    • pp.305-313
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    • 2017
  • A robust finite element based reinforced concrete bridge deck corrosion initiation model is applied for time-dependent probabilistic sensitivity analysis. The model is focused on uncertainties in the governing parameters that include variation of high performance concrete (HPC) diffusion coefficients, concrete cover depth, surface chloride concentration, holidays in reinforcements, coatings and critical chloride threshold level in several steel reinforcements. The corrosion initiation risk is expressed in the form of probability over intended life span of the bridge deck. Conducted study shows the time-dependent sensitivity analysis to evaluate the significance of governing parameters on chloride ingress rate, various steel reinforcement protection and the corrosion initiation likelihood. Results from this probabilistic analysis provide better insight into the effect of input parameters variation on the estimate of the corrosion initiation risk for the design of concrete structures in harsh chloride environments.

PROBABILISTIC SEISMIC HAZARD ANALYSIS FOR NUCLEAR POWER PLANTS - CURRENT PRACTICE FROM A EUROPEAN PERSPECTIVE

  • Klugel, Jens-Uwe
    • Nuclear Engineering and Technology
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    • v.41 no.10
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    • pp.1243-1254
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    • 2009
  • The paper discusses the methodology and the use of probabilistic seismic hazard analysis (PSHA) for nuclear power plants from a European perspective. The increasing importance of risk-informed approaches in the nuclear oversight process observed in many countries has contributed to increasing attention to PSHA methods. Nevertheless significant differences with respect to the methodology of PSHA are observed in Europe. The paper gives an overview on actual projects and discusses the differences in the PSHA-methodology applied in different European countries. These differences are largely related to different approaches used for the treatment of uncertainties and to the use of experts. The development of a probabilistic scenario-based approach is identified as a meaningful alternative to the development of uniform hazard spectra or uniform confidence spectra.

Reliability Analysis of Hybrid Rocket using Monte-Carlo Simulation (몬테 카를로 시뮬레이션을 이용한 하이브리드 로켓의 신뢰성 분석)

  • Moon, Keunhwan;Kim, Wanbeom;Lee, Jungpyo;Choi, Jooho;Kim, Jinkon
    • Journal of Aerospace System Engineering
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    • v.7 no.4
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    • pp.1-11
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    • 2013
  • In this study, probabilistic reliability analysis was conducted for hybrid rocket performance using Monte-Carlo Simulation. For the accuracy, reliability analysis was performed with experimental data. To simplify the analysis process, the oxidizer was supplied with constant pressure, so that pressure variation with time can be eliminated. And time-space averaged regression rate model was used. The regression rate is obtained with a series of experiments. For reliability analysis of thrust, constant exponent of regression rate is assumed that has probabilistic character. So, the efficiency of characteristic velocity has also probabilistic values. As a results, probability distribution of the thrust is obtained by Monte-Carlo simulation using random samples of the input parameter and validated under the 95% confidence level.