• Title/Summary/Keyword: 신뢰성지수

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Development of the Reliability Index for Improving the Reliability of the Manufacturing Equipment (제조업 장비의 신뢰성 향상을 위한 신뢰성지수 개발)

  • Yu, Sangwoo;Park, Jungwon;Kim, Min;Hong, Jungpyo;Oh, Geuntae;Na, Yoonkyoon
    • Journal of Applied Reliability
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    • v.16 no.3
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    • pp.245-253
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    • 2016
  • Purpose: The purpose of this study is to measure the reliability of complex equipment. Reliability of product is one of the most important factor to achieve competitiveness in the market. While there were many researches for assessing the reliability on components and modules, research on quantitative assessment tool for equipment with many component was little because of equipment's complexity. Methods: In this article, we developed index to assess reliability management system by using IEC 60300 and Reliability Management Tool-kit. With MIR and BARS, we developed reliability index clauses relevant to reliability activities and found weight factor for each clause by survey on experts. Results: The results of this study were as follows; reliability index that can assess both management side and technology side of the company was developed. Conclusion: Using this index, we assessed the reliability of a manufacturing equipment and found out the current reliability level of the manufacturing equipment, and derived improvement points.

A Models of Economic Analysis in Safety Diagnosis for Remodeling Strategies of Apartment Housing (공동주택의 리모델링 전략을 위한 안전진단의 경제성분석 모델)

  • Seo Kwang-Jun;Choi Mi-Ra;Shin Nam-Soo
    • Korean Journal of Construction Engineering and Management
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    • v.6 no.4 s.26
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    • pp.164-171
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    • 2005
  • The importance of the life cycle cost analysis(LCCA) for apartment housing remodeling projects has been fully recognized over the last decade. Accordingly theoretical models, guidelines, and supporting software systems were developed for the life cycle cost analysis of apartment housing remodeling systems. However, the level of consensus on LCCA results is still low due to the lack of reliable data on remodeling activities for safety diagnosis. in order to predict the reliability based LCCA of the given case, suggested the remodeling strategies level after reviewing other related materials. Apply the real information of the economic index. And based on such analytical measures, remodeling and operation cost and LCC in remodeling strategies level have been predicted; suggests the basic information about remodeling interventions level for the apartment housing. The LCC analysis models and the fuzzy logic based safety assessment presented in this study can greatly contribute to the value-oriented design alternative selection, estimation of the economic analysis, and the allocation of budget for apartm.

Structural Reliability Evaluation Considering Construction Stage and Epistemic Uncertainty of Suspension Bridges (현수교의 시공절차와 인위적 불확실성을 고려한 구조신뢰성 평가)

  • Han, Sung Ho;Shin, Jae Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3A
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    • pp.181-188
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    • 2009
  • This study presented the basic data for determining reasonable construction method and evaluating the structural safety of suspension bridges. The analytical program was developed to conduct initial shape and natural frequency analysis, construction stage analysis and reliability analysis considering construction sequences. This program was based on analysis models of suspension bridges and reliability theories used in the previous study. A construction method was established considering various construction variables such as construction order and construction direction of girder and synchronized construction of main and side span etc. The dynamic construction analysis by a construction scheme was conducted with the developed program. Benefits of the characteristic analysis by the construction scheme was presented estimating structural response of critical members respectively. Structural reliability analysis by construction stage was conducted considering aleatory uncertainties. The safety of suspension bridges by established construction method was quantitatively estimated using reliability index and failure probability. Analytical results were re-estimated considering epistemic uncertainties, and critical percentile distributions of risk at the construction stage were presented using the frequency histogram.

The Stochastic Finite Element Analysis and Reliability Analysis of the Cable Stayed Bridge Considered to Correlation of the Random Variable (확률변수의 상관성을 고려한 사장교의 확률유한요소해석 및 신뢰성해석)

  • Han, Sung Ho;Shin, Jae Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.21-33
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    • 2006
  • The reliability analysis can be conducted more effectively by formulating the stochastic finite element method suitable for the reliability theory about the cable stayed bridge. After conducting the initial equilibrium analysis of the cable stayed bridge, the program which can conduct the linear and nonlinear stochastic finite element analysis using the perturbation method and the reliability analysis considered to the correlation of the random variable is developed. Using the results of this program about the cable stayed bridge, the characteristic of the node displacement, element force and cable tension according to the correlation of the random variable is investigated quantitatively. Also the reliability index and the failure probability are examined by the compounding the correlation of the random variable.

Load & Resistance Factors Calibration for Sliding and Overturning Limit State Design of Perforated Caisson Breakwater (유공케이슨 방파제 활동 및 전도 한계상태설계를 위한 하중저항계수 보정)

  • Kim, Dong Hyawn
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.458-464
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    • 2020
  • Calibration of load-resistance factors for the limit state design of perforated caisson breakwaters are presented. Reliability analysis of 12 breakwaters in nationwide ports was conducted. Then, partial safety factors and load-resistance factors were sequentially calculated according to target reliability index. Load resistance factors were optimized to give one set of factor for limit state design of breakwater. The breakwaters were redesigned by using the optimal load resistance factor and verified whether reliability indices larger than the target value. Finally, some load-resistance factors were proposed by changing target reliability index.

Design Sensitivity and Reliability Analysis of Plates (판구조물의 설계감도해석 및 신뢰성해석)

  • 김지호;양영순
    • Computational Structural Engineering
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    • v.4 no.4
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    • pp.125-133
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    • 1991
  • For the purpose of efficiently calculating the design sensitivity and the reliability for the complicated structures in which the structural responses or limit state functions are given by implicit form, the probabilistic finite element method is introduced to formulate the deterministic design sensitivity analysis method and incorporated with the second moment reliability methods such as MVFOSM, AFOSM and SORM. Also, the probabilistic design sensitivity analysis method needed in the reliability-based design is proposed. As numerical examples, two thin plates are analyzed for the cases of plane stress and plate bending. The initial yielding is defined as failure criterion, and applied loads, yield stress, plate thickness, Young's modulus and Poisson's ratio are treated as random variables. It is found that the response variances and the failure probabilities calculated by the proposed PFEM-based reliability method show good agreement with those by Monte Carlo simulation. The probabilistic design sensitivity evaluates explicitly the contribution of each random variable to probability of failure. Further, the design change can be evaluated without any difficulty, and their effect on reliability can be estimated quickly with high accuracy.

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Probabilistic Analysis of Vertical Drains using Hasofer-Lind Reliability Index (신뢰성지수를 이용한 연직배수공법의 확률론적 해석)

  • Kim, Seong-Pil;Heo, Joon;Bong, Tae-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.6
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    • pp.1-6
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    • 2011
  • The conventional factor of safety as used in geotechnical engineering does not reflect the degree of uncertainty of the relevant parameters. Then in the geotechnical engineering, there have been efforts to reflect the uncertainties of the geotechnical properties through probabilistic analysis. In this study, a practical method for probabilistic analysis using the Hasofer-Lind reliability index is introduced. The method is based on the perspective of an ellipsoid that just touches the failure surface in the original space of the variables. The method is applied to prefabricated vertical drains (PVD) and compared with the result of Monte Carlo Simulation method.

Suggestion for Train Vibration Equations based on Change in Track System (궤도구조 변경에 따른 열차 진동 추정식 제안)

  • 김응록;박연수;강성후;박선준;김흥기
    • Journal of the Korean Society for Railway
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    • v.5 no.1
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    • pp.48-54
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    • 2002
  • This research estimated decreased vibration level as quantitative according to change of track system on Seoul Subway Line No. 1 from existing ballasted track system(Pandrol type clip) to concrete track system(Youbgdan type isolation rubber clip). Following change to concrete system, vibration level at tunnel floor decreased between 4-8dB(V). Vibration equations suggested in this paper consider the velocity of train and can estimate quantitative vibration response. These are divided by ultimate limit state($\beta$=0), serviceability limit state($\beta$=1.28) and safety state($\beta$=3), respectively. The reliability index, $\beta$=0, means 50% data line obtained by least squares best-fit line. The reliability index $\beta$=1.28 and 3 represent boundaries below 90% and 99.9% respectively.

Suggestion of Vibration Criteria for Fresh Concrete Considering Early Strength Increase (Fresh 콘크리트의 초기 강도 증가를 고려한 진동규준치 제안)

  • Park, Sun-Joon;Park, Yeon-Soo;Kang, Sung-Hoo;Kim, Hong-Ki;Kim, Eung-Rok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.6
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    • pp.453-460
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    • 2002
  • In this paper, vibration criteria for fresh concrete are suggested considering relationship of strength and ages of concrete. Vibration criteria of fresh concrete subjected to construction vibration are not to be certain in abroad countries without question within a country. Before 12 hours cured, vibration criterion is suggested 0.25 cm/s. Used 4.0 cm/s by vibration criterion after 28 days. And the interval extent used relation with strength and ages of concrete. Vibration criteria proposed in this paper are thought may satisfy properties of fresh concrete as well as generally used those in domestic. Also, the actual ground vibrations due to pile driving have been measured, and data are analyze using the nitration equation applying to reliability index.

Load & Resistance Factors Calibration for Front Covered Caisson Breakwater (소파블록 피복제 제체의 한계상태설계를 위한 하중저항계수 보정)

  • Kim, Dong Hyawn;Huh, Jungwon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.6
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    • pp.293-297
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    • 2021
  • Calibration of load-resistance factors for the limit state design of front covered caisson breakwaters were presented. Reliability analysis of the breakwaters which are constructed in Korean coast was conducted. Then, partial safety factors and load-resistance factors were sequentially calculated according to target reliability index. Load resistance factors were optimized to give one set of factor for limit state design of breakwater. The breakwaters were redesigned by using the optimal load resistance factor and verified whether reliability indices larger than the target value. Finally, load-resistance factors were compared with foreign country's code for verification.