• Title/Summary/Keyword: Reliability Design

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A Reliability Analysis Application and Comparative Study on Probabilistic Structure Design for an Automatic Salt Collector (자동채염기의 확률론적 구조설계 구현을 위한 신뢰성 해석 응용과 비교연구)

  • Song, Chang Yong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.12
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    • pp.70-79
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    • 2020
  • This paper describes a comparative study of characteristics of probabilistic design using various reliability analysis methods in the structure design of an automatic salt collector. The thickness sizing variables of the main structural member were considered to be random variables, including the uncertainty of corrosion, which would be an inevitable hazard in the work environment of the automatic salt collector. Probabilistic performance functions were selected from the strength performances of the automatic salt collector structure. First-order reliability method, second-order reliability method, mean value reliability method, and adaptive importance sampling method were applied during the reliability analyses. The probabilistic design performances such as reliability probability and numerical costs based on the reliability analysis methods were compared to the Monte Carlo simulation results. The adaptive importance sampling method showed the most rational results for the probabilistic structure design of the automatic salt collector.

A Study on the Effect of Design Reliability and Periodic Inspection Cycle on Storage Reliability : Focusing on One-shot Logistic Equipment System (설계신뢰도 및 정기검사주기가 저장신뢰도에 미치는 영향에 관한 연구 : 일회성 군수장비 시스템을 대상으로)

  • Chu, Yeon-Won
    • Journal of the Korea Convergence Society
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    • v.9 no.7
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    • pp.223-230
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    • 2018
  • In the case of a one-shot logistic equipment system that has been stored for a long time, reliability changes with the passage of time. Therefore, when the time comes to use, the storage reliability of the product is an important quality characteristic, and the existing studies have focused on the research for calculating the optimal period inspection cycle to improve the storage reliability. In this study, we analyzed the influence of the two factors on the storage reliability at the convergence point by analyzing the design reliability as well as the periodic inspection cycle. To do this, we applied the existing Martinez storage reliability model to the missile, a representative product of a one-shot system, and analyzed the quantitative effects of the design reliability and the periodic inspection cycle. From the results of the analysis, it was confirmed that the maintenance of the periodic inspection cycle is more important for the improvement of the storage reliability than the design reliability in the design reliability category of the current product.

Sensitivity and Reliability Analysis of Elate (판 구조물의 감도해석 및 신뢰성해석)

  • 김지호;양영순
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1991.10a
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    • pp.57-62
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    • 1991
  • For the purpose of developing the method for efficiently calculating the design sensitivity and the reliability for the complicated structure such as ship structure, 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 needed in the reliability-based design is performed. The reliability analysis is carried out for the initial yielding failure, in which the derivative derived in the deterministic desin sensitivity is used. The present PFEM-based reliability method shows good agreement with Monte Carlo method in terms with the variance of response and the associated probability of failure even at the first or first few iteration steps. The probabilistic design sensitivity analysis evaluates explicitly the contribution of each random variable to probability of failure. Further, the reliability index variation can be easily predicted by the variation of the mean and the variance of the random variables.

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Application of Reliability Technology for Sustainable Product Redesign (지속가능한 제품재설계를 위한 신뢰성기법의 적용방법)

  • Lee, Jong-Beom;Jung, Won
    • Journal of Applied Reliability
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    • v.9 no.4
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    • pp.343-349
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    • 2009
  • One of the recent hot issues in the manufacturing business is how to incorporate environmental attributes into product and process design. Design for environment considers the potential environmental impact of a product throughout its life-cycle. In the case of something breaks, it can become waste immediately, hence reliability and durability is the essential part of product design. This paper presents reliability technology for sustainable product design to improve the product longevity that extends performance life, serviceability and durability. The presented method will help to develop a sound design and avoid weak links to minimize the waste.

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OPTIMAL RELIABILITY DESIGN FOR THIN-WALLED BEAM OF VEHICLE STRUCTURE CONSIDERING VIBRATION

  • Lee, S.B.;Baik, S.;Yim, H.J.
    • International Journal of Automotive Technology
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    • v.4 no.3
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    • pp.135-140
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    • 2003
  • In the deterministic optimization of a structural system, objective function, design constraints and design variables, are treated in a nonstatistical fashion. However, such deterministic engineering optimization tends to promote the structural system with lest reliability redundancy than obtained with conventional design procedures using the factor of safety. Consequently, deterministic optimized structures will usually have higher failure probabilities than unoptimized structures. Therefore, a balance must be developed between the satisfactions of the design requirements and the objectives of reducing manufacturing cost. This paper proposes the reliability-based design optimization (RBDO) technique, which enables the optimum design that considers confidence level for the vibration characteristics of structural system. Response surface method (RSM) is utilized to approximate the performance functions describing the system characteristics in the RBDO procedure. The proposed optimization technique is applied to the pillar section design considering natural frequencies of a vehicle structure.

Midship Section Design of Ship Structures Based on Reliability Analysis (신뢰성 해석에 기초한 선체 중앙단면 설계)

  • Lee, Joo-Sung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.5
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    • pp.507-512
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    • 2011
  • This study is concerned with the reliability analysis and its based design of midship section against the ultimate bending strength. Eight bulk carriers and seven oil tankers over 100m length are chosen for the present study. Target reliability indices for the two ship types have been derived based on the results reliability analysis of the present ship models. Reliability-based structural design codes are proposed for use in design of midship section of bulk carriers and oil tankers. The design codes proposed in this study have been successfully applied to re-design of midship section of the present ship types. It has been found that the proposed codes can provide more uniform structural design results.

Study of the Efficient Aerodynamic Shape Design Optimization Using the Approximate Reliability Method (근사신뢰도기법을 이용한 효율적인 공력 형상 설계에 관한 연구)

  • Kim Suwhan.;Kwon Jang-Hyuk
    • 한국전산유체공학회:학술대회논문집
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    • 2004.10a
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    • pp.187-191
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    • 2004
  • The conventional reliability based design optimization(RBDO) methods require high computational cost compared with the deterministic design optimization(DO) methods. To overcome the computational inefficiency of RBDO, single loop methods have been proposed. These need less function calls than that of RBDO but much more than that of DO. In this study, the approximate reliability method is proposed that the computational requirement is nearly the same as DO and the reliability accuracy is good compared with that of RBDO. Using this method, the 3-D viscous aerodynamic shape design optimization with uncertainty is performed very efficiently.

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A New Reliability-Based Optimal Design Algorithm of Electromagnetic Problems with Uncertain Variables: Multi-objective Approach

  • Ren, Ziyan;Peng, Baoyang;Liu, Yang;Zhao, Guoxin;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.704-710
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    • 2018
  • For the optimal design of electromagnetic device involving uncertainties in design variables, this paper proposes a new reliability-based optimal design algorithm for multiple constraints problems. Through optimizing the nominal objective function and maximizing the minimum reliability, a set of global optimal reliable solutions representing different reliability levels are obtained by the multi-objective particle swarm optimization algorithm. Applying the sensitivity-assisted Monte Carlo simulation method, the numerical efficiency of optimization procedure is guaranteed. The proposed reliability-based algorithm supplying multi-reliable solutions is investigated through applications to analytic examples and the optimal design of two electromagnetic problems.

Reliability Analysis of Design Wind Load Combination for Support Structures of Subsidiary Road Facilities (도로 부대시설 지주구조물 설계를 위한 풍하중조합의 신뢰도 분석)

  • Kim, Gneok;Ahn, Sang-Sup;Kim, Ho-Kyung;Cho, Kyung-Sik;Paik, Inyeol
    • International Journal of Highway Engineering
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    • v.19 no.4
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    • pp.27-36
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    • 2017
  • PURPOSES : The purpose of this study is to perform a reliability analysis of the proposed wind load combination which governs the design of support structures of subsidiary road facilities, and to evaluate whether the target reliability of the design is satisfied. METHODS : The statistical estimation method is applied and the design period of the support structure is used to obtain the statistical property of the wind load. In addition, the statistical properties of the strength of support structures are obtained from a literature review and simulation study. Actual support structures are designed by the proposed load combination and are used as the examples to examine if the target reliability is obtained. RESULTS : The result of the reliability analysis performed by using the statistical properties of load and resistance for the support structure in this study indicates that the proposed wind load combination satisfied the target reliability index of the design. Also, the convenience of the design is achieved by adopting the same design wind velocity given in the bridge design code by applying the wind velocity ratio defined for the design period of the support structure. CONCLUSIONS : It is presented that the design using the wind load combination proposed in this study achieved the target reliability index and the design wind load for different design periods can be conveniently defined by applying the velocity ratio proposed in this study.

Evaluation of Partial Safety Factors of Armor Units by Inverse-Reliability Analysis (역해석법에 의한 피복재의 부분안전계수 산정)

  • Lee, Cheol-Eung;Park, Dong-Heon
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.149-156
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    • 2008
  • A reliability model of Level II AFDA is developed to analyze the stability of armor units on the sloped coastal structures. Additionally, the partial safety factors of random variables related to armor units can be straightforwardly evaluated by applying the inverse-reliability method in which influence coefficients and uncertainties of random variables, and target probability of failure are combined directly. In particular, a design equation for armor units is derived in terms of the same criteria as deterministic design method in order to apply the reliability-based design method of Level I without some understanding to the reliability analysis. Finally, it is confirmed that several results redesigned by the reliability-based design method of Level I have satisfactorily agreement with results of CEM as well as those of Level II AFDA.

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