• 한국산업융합학회 논문집
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• 제10권1호
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• pp.47-54
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• 2007

Bridge decks are one of the main structural components that are most suitable for utilizing the advantages of FRP materials due to the high strength weight ratio of FRP materials. Design codes for the design of FRP bridge decks should be established to apply FRP materials for bridge decks effectively. At present, design codes are relatively well established for the use of FRP materials as reinforcements in concrete structures. However, design codes have not yet been provided for the structures made of FRP as a main construction material. In this study, for the purpose of preparing design code provisions, reliability analyses were performed to evaluate target level of safety and serviceability on GFRP decks. Based on the results, several guidelines for the development of design codes are suggested.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.331-338
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• 2013

A new reliability calculation method is proposed based on design sensitivity analysis by the finite element method for nonlinear performance constraints in the optimal design of electromagnetic devices. In the proposed method, the reliability of a given design is calculated by using the Monte Carlo simulation (MCS) method after approximating a constraint function to a linear one in the confidence interval with the help of its sensitivity information. The validity and numerical efficiency of the proposed sensitivity-assisted MCS method are investigated by comparing its numerical results with those obtained by using the conventional MCS method and the first-order reliability method for analytic functions and the TEAM Workshop Problem 22.

• 한국도로학회논문집
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• 제18권4호
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• pp.77-82
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• 2016

PURPOSES : This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions. METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables. RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63. CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1642-1647
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• 2007

The aim of this research is to implement a design framework based on reliability analysis and make it possibly used for a reliable and robust design under uncertainties. Different types of reliability methods and algorithms are programmed to explore their characteristics. In our work, RIA and the PMA are employed for formulating the reliability analysis problems. A number of reliability methods are introduced in this program such as FORM, AMV/AMV+ and MCS. Reliability analysis can be easily performed with this tool box only if a drive file is ready to run. Users need to select random design variables and define their distributions and correlation.

• 한국공작기계학회논문집
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• 제13권6호
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• pp.107-113
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• 2004

This paper presents the pillar section optimization technique considering the reliability of the vehicle body structure consisted of complicated thin-walled panels. The response surface method is utilized to obtain the response surface models that describe the approximate performance functions representing the system characteristics on the section properties of the pillar and on the mass and the natural frequencies of the vehicle B.I.W. The reliability-based design optimization on the pillar sections Is performed and compared with the conventional deterministic optimization. The FORM is applied for the reliability analysis of the vehicle body structure. The developed optimization system is applied to the pillar section design considering the fundamental natural frequencies of passenger car body structure. By applying the proposed RBDO technique, it can be possible to optimize the pillar sections considering the reliability that engineers require.

• Advances in concrete construction
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• 제14권2호
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• pp.131-137
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• 2022

Based on the design of reinforced concrete columns in Chinese design codes, the failure function of reinforced concrete (RC) columns cannot be expressed as a linear function. This makes it difficult to reveal the level of reliability control in Chinese design code. Therefore, the failure function of dimensionless form is established in this paper, and the typical components (Industrial plant columns) are selected for analysis. At last, numerical simulation proves that the proposed model can be used to analysis reliability of columns. The results based on this model indicate that there is a strong difference in the reliability of RC columns designed with different design parameters, and the reliability would be lower when the eccentricity produced by crane load is smaller.

• 한국신뢰성학회지:신뢰성응용연구
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• 제5권1호
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• pp.181-192
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• 2005

In this paper, we consider a process for design for reliability(DFR) in design and development phases. The procedure of GE for DFR is applied to develope and analyze a washing machine with required reliability and the detailed procedure is proposed.

• 대한토목학회논문집
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• 제39권1호
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• pp.13-24
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• 2019

이 연구에서는 국내 도로교 한계상태설계법에서 콘크리트부재의 설계를 위하여 적용하고 있는 재료계수의 문제점을 제기하고, 잘 정립된 최적화 과정에 의한 재료계수를 제안하였다. 신뢰도분석을 통하여 현 설계기준의 하중계수와 제안 재료계수가 목표신뢰도지수 보다 높은 신뢰도수준을 확보하고 있음을 보이고, 역신뢰도해석을 통하여 목표신뢰도지수를 잘 근사할 수 있는 하중계수를 제시하였다. 유로코드에서 제시하고 있는 기본 개념에 근거하여 신뢰도기반 하중-재료계수 결정법을 정식화하였다. 제안된 접근법이 신뢰도개념에 의하여 유도되었지만, 이 접근법에 의하여 계산된 하중-재료 계수가 목표신뢰도지수를 정확히 만족시키지 못하는 요인으로서 재료와 부재간에 존재하는 불확실성의 차이를 지적하고, 이러한 차이를 고려하지 않는 유로코드의 개념적 문제점을 제기하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1989년도 가을 학술발표회 논문집
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• pp.34-39
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• 1989

Recent trends in design standards development have encouraged the use of probabilistic limit sate design concepts. Reliability analysis adopted in those advanced countries have the potentials that they afford for symplifying the design Process arid placing it on a consistent reliability based for various construction materials. This study is proposed in the reliability analysis of plane frame structures using second-order moment method(Level-II they). Lind-Hasofer's minimum distance method is use in the derivation of an mathematical algorithm as well as an determination of Correlation cofficients, reliability index and total reliability index depending on the multiple failure modes. In addition. This study is employed as a practical tool for the approximate reliability analysis. Results of the numerincal analysis showed that the difference between the reliability index of the failure probability of the multiple failure modes and the total reliability index of the failure probability with the simultaneous failure modes deviated nearly 3∼10% depending on tile performance functions.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.63-71
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• 2007

During the design phase of a product, reliability and design engineers are called upon to evaluate the reliability of the system, The question of how to meet target reliability for the system arises when estimated reliability or cost is inadequate. This then becomes a problem of reliability allocation and system structure design. This study proposes the optimization methodology to achieve target reliability with minimum cost through construction of the cost function of system. In cost function, total cost means the sum of initial cost, repair cost and maintenance cost. This study constructs optimization problem about system structure design and reliability allocation using cost function. This problem constructed is solved by Multi-island Genetic Algorithm(MIGA), and applies to urban transit brake system. Current brake system of the urban transit is series system. Series system is the simplest and perhaps one of the most common system, but it demands high reliability and maintenance cost because all components must be operating to ensure system operation. Thus this study makes a comparative study by applying k-out-of-n system to brake system. This methodology presented can be a great tool for aiding reliability and design engineers in their decision-makings.