• Title/Summary/Keyword: Failure Mode and Effects Analysis

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Effect of Span-to-Depth Ratio on Behavior and Capacity in Composite Structure of Sandwich System (샌드위치식 복합구조체의 셀(Cell)형상비가 거동과 성능에 미치는 영향)

  • 정연주;정광회;김병석;박성수;황일선
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.10a
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    • pp.73-78
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    • 2000
  • This paper describes the effect of span-to-depth ratio, which describes aspect of cell formed with top diaphragm steel plate, on capacity in composite steel-concrete structure of sandwich system. The span-to-depth ratio \ulcorner load-carrying mechanism and load-distribution capacity of structure. Therefore, stress levels of members and load-resis\ulcorner of system vary according to span-depth ratio. In this study, numerical nonlinear analysis was performed to various ratio for two types(MA, MB) composite structure of sandwich system to analyze the influence of span-to-depth ratio or, behavior. The difference of load-carrying mechanism and stress of members results from analysis results, then bas\ulcorner differences, the effects of span-to-depth ratio on shear capacity, flexural capacity and load-resistance capacity were analyze effects on failure mode and ductility were briefly. As a results of this study, as span-to-depth ratio increases, \ulcorner bottom steel plate and concrete lower. This implies an increase in effective flexural and shear capacity. Therefore lo\ulcorner capacity of structure improves as span-to-depth ratio increases, Especially, the effect is greate in shear than flexural span-to-depth ratio increases, this difference between flexural and shear capacity may change failure mode and ductility. span-to-depth ratio increases capacity increases more than flexural capacity, we should expect that structural behavior mode gradually change from shear to flexural and ductility of structure gradually improves.

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Life Cycle Cost & Reliability Analysis of Quaywall Design Parameters (안벽 설계변수의 신뢰성 해석과 생애주기비용 분석)

  • Kim, Hong-Yeon;Yoon, Gil-Lim;Yoon, Yeo-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.508-518
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    • 2008
  • Reliability and sensitivity analysis of the design parameters for a section of caisson type quaywall which is the most applicable in Korea were performed. It was tried to estimate probabilities of failure for the system of the multiple failure modes and to analyze LCC in the quaywall structure. The reliability analysis was performed by FORM. Also, sensitivity indices were estimated using the reliability indices, which may be used inferring effects of each design parameter on the reliability indices. As a result, the coefficient of friction between caisson and rubble, the moment by self weight and the moment of resistance mostly affected on the reliability indices in the sliding, overturning and foundation failure, respectively. System reliability theorem was applied in order to estimate the probabilities of failure for the system of the multiple failure modes. As the results of estimation of the probabilities of failure for the system, all cases were more conservative than those for the elements, according to both failure mode and load combination applied to series system. It entirely exceeded the target reliability index, but it was consistent with the theorem. According to the optimum LCC with the width of the caisson, the probability of failure exceeded the target probability of failure at then time. Therefore, it was judged to be insufficient to the practical application.

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Evaluation of Deformation and Strength of Wall Thinne Pipes by Finite Element Analysis (감육배관의 유한요소해석에 의한 변형 및 강도 평가)

  • NAM KI-WOO;AHN SEOK-HWAN;LEE SOO-SIG;KIM JIN-WOOK;YOON JA-MUN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.5 s.66
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    • pp.65-70
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    • 2005
  • Fracture behavior and pipe strength are very important to the integrity of energy plants, ocean structures, and so forth. The pipes of energy plants and ocean structures are subject to local wall thinning, resulting from severe erosion-corrosion damage. Recently, the effects of local wall thinning on fracture strength and fracture behavior of piping systems have been the focus of many studies. In this paper, the elasto-plastic analysis is performed by FE code ANSYS on straight pipes with wall thinning. We evaluated the failure mode, fracture strength and fracture behavior, using FE analysis. Also, the effect of the axial strain on deformations and failure modes was estimated by FE analysis.

Fault Tree Analysis and Failure Mode Effects Analysis for Software Security Improvements in Mobile Banking Information Systems (모바일 뱅킹 정보시스템의 소프트웨어 보안성 개선을 위한 고장 트리 분석과 고장 유형 영향 분석)

  • Kim, So Young;Kim, Myong Hee;Park, Man-Gon
    • Journal of Korea Multimedia Society
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    • v.18 no.11
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    • pp.1342-1350
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    • 2015
  • Due to rapid development of mobile device technologies, the mobile banking through Internet has become a major service of banking information systems as a security-critical information systems. Recently, lots of mobile banking information systems which handle personal and transaction information have been exposed to security threats in vulnerable security control and management processes, mainly software systems. Therefore, in this paper, we propose a process model for software security improvements in mobile banking information system by application of fault tree analysis(FTA) and failure modes and effects analysis(FMEA) on the most important activities such as 'user authentication' and 'access control' and 'virus detection and control' processes which security control and management of mobile banking information systems are very weak.

Evaluating Service Reliability focused on Failure Modes (실패모드에 근거한 서비스 신뢰도 평가모델)

  • Oh, Hyung-Sool
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.3
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    • pp.133-141
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    • 2012
  • Service and manufacturing companies' efforts are increasingly focused on utilizing services to satisfy customers' needs and survive in today's competitive market environment. The value of services depends mainly on service reliability that is identified by satisfaction derived from the relationship between customer and service provider. In this paper, we extend concepts from the failure modes and effects analysis of tangible systems to services. We use an event-based process model to facilitate service design and represent the relationships between functions and failures in a service. The objective of this research is to propose a method for evaluating service reliability based on service processes using fuzzy failure mode effects analysis (FMEA) and grey theory. We define the failure mode of service as interaction ways that can be failed in a service delivery process. The fuzzy set theory is used to characterize service reliability based on linguistic terms during FMEA. Grey theory is employed to determine the degree of relation and ranking among risk factors that are represented as potential failure causes. To demonstrate implementation of the proposed method, we use a case study involving a typical automotive service operation.

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Application Study on FMEA(Failure Mode and Effect Analysis) for Waterjet-lifter of Deep-Sea Manganese Nodule Miner (심해저 망간단괴 집광시스템의 물제트부양장치에 대한 FMEA 적용 연구)

  • Choi, Jong-Su;Hong, Sup;Lee, Tae-Hee;Kim, Hyung-Woo;Yeu, Tae-Kyeong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.6
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    • pp.32-38
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    • 2009
  • An FMEA for the waterjet-lifter of a DSNM is performed to prevent the occurrence of device failure. A waterjet-lifter raises and transports manganese nodules from the deep-sea floor up to a somewhat elevated place, from which a pin-scraper transports the lifted nodules to the inner space of the DSNM. A concept design for a device using the axiomatic design methodology is shown as the mapping between the functional domain and physical domain. The FMEA for a DSNM is introduced briefly and the rating criteria of severity, occurrence, and detection for the DSNM are defined. The FMEA of the functional requirements of a DSNM device is accomplished. Three kinds of failure modes, as well as their effects and causes, are predicted. Current design control methods for detecting potential failures, such as physical or computational experiments, design confirmation, and mathematical calculation, are described and the recommended actions for several significant causes are suggested.

A Study on Project Management for Product Development using Quality Tools (품질도구를 활용한 제품개발 프로젝트관리)

  • Park, Young Hyun
    • Journal of Korean Society for Quality Management
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    • v.45 no.4
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    • pp.665-676
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    • 2017
  • Purpose: The purpose of this paper proposes an effective and systematic methods of risk management in product development project. Methods: This paper first discusses what risk factors be considered during product development period and then presented a model for preventive risk management. For that, this paper proposes how to evaluate the risk factors and risk events, and how to select prevention action for managing risk factors effectively. For this process, this paper uses well-known quality tools such as House of Quality (HOQ) and Failure Mode and Effects Criticality Analysis (FMECA) methods. Results: There is an inherent need for the development of robust risk management framework in order for product development projects to be successful. The identification and quantification of risk factors, risk events, and prevention actions can have significant effects on the success of a product development projects. Project managers can implement the proposed model to improve project success. Conclusion: The findings showed that this method would be effective for project managements in dealing with risk management issues in product development projects. This method presented would be an one of good guidelines for practitioners in the industry.

Scenario Planning and Risk Failure Mode Effect and Analysis (RFMEA) based Management

  • Paul, Virendra Kumar;Basu, Chaitali
    • Journal of Construction Engineering and Project Management
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    • v.6 no.2
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    • pp.24-29
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    • 2016
  • This paper elaborates the significance of scenario planning in risk management, and presents an integrated approach which takes into account the 'Risk Events' derived from scenario planning for risk prioritisation. This research integrates scenario planning with Risk Failure Mode and Effect Analysis (RFMEA) through examples from construction litigations of project schedule and cost overrun cases as a simplified approach to project risk management. The proposed methodology incorporates scenarios developed from realistic events of dispute and arbitration cases from construction projects, and thereby increasing potential to foresee risks and their effects well in advance. The results from this methodology shall be validated against outcome of survey study conducted by KPMG-PMI (2013) on project schedule and cost overruns that was based on Ministry of Statistics and Programme Implementation (MoSPI) Project Monitoring data for 2012-13.

FMEA and FTA for Reliability Analysis of Hybrid Rocket Motor (하이브리드 로켓 모터의 신뢰성 분석을 위한 FMEA 및 FTA)

  • Moon, Keun Hwan;Kim, Dong Seong;Choi, Joo Ho;Kim, Jin Kon
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.4
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    • pp.27-33
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    • 2013
  • In this study, the FMEA and FTA for reliability analysis of hybrid rocket motor are performed, that was designed in the Hybrid Rocket Propulsion Laboratory of Korea Aerospace University. In order to carry out these analyses the structure of the hybrid rocket motor is hierarchically divided into 36 parts down to the component level and FMEA is carried out with 72 failure modes. Reliability is assessed based on the FMEA, and the results are used in the FTA to evaluate the overall system reliability. In the FMEA, the relationship between the cause and failure modes, effects and their risk priorities are evaluated qualitatively. 27 failure modes are chosen as those with the critical severity that should be improved with priority. As a result of the FMEA / FTA study, a series of design or material changes are made for the improvement of reliability.

Active Earth Pressure behind Rigid Retaining Wall Rotating about the Base (저점을 중심으로 회전하는 강성옹벽에 작용하는 주동토압)

  • 백규호
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.193-203
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    • 2004
  • Arching effects in backfill materials generate a nonlinear active earth pressure distribution on a rigid retaining wall with rough face, and arching effects on the shape of the nonlinear earth pressure distribution depends on the mode of wall movement. Therefore, the practical shape of failure surface and arching effect in the backfill changed with the mode of wall movement must be considered to calculate accurate magnitude and distribution of active earth pressure on the rigid wall. In this study, a new formulation for calculating the active earth pressure on a rough rigid retaining wall rotating about the base is proposed by considering the shape of nonlinear failure surface and arching effects in the backfill. In order to avoid mathematical complexities in the calculation of active earth pressure, the imaginary failure surface composed of four linear surfaces is used instead of the nonlinear failure surface as failure surface of backfills. The comparisons between predictions from the proposed equations and existing model test results show that the proposed equations produce satisfactory predictions.