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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A manufacturing failure mode avoidance framework for aerospace manufacturing

Goodland, J., Campean, Felician, Caunce, A., Victory, J.L., Jupp, M.L. January 2013 (has links)
No / Enhancement in productivity and cost effectiveness of high value manufacturing requires a process based management strategy. This paper introduces a Manufacturing Failure Mode Avoidance (MFMA) framework based on 4 high level process steps and underpinned by a sequence of engineering and process analysis tools to support a structured function-based decomposition of complex manufacturing processes and a continuous flow of information towards the development of robust control plans. The approach draws from experience in the automotive industry, where Failure Mode Avoidance (FMA) has been strategically adopted to achieve a step change in the effectiveness of business and engineering processes associated with the product creation processes. The paper presents a case study of the deployment of the MFMA framework to an aircraft manufacturing process followed by a broader discussion of the strength of the approach and its generic applicability to complex high value manufacturing engineering.
2

Structural performance of staircase post connection systems under monotonic and reversed cyclic static loads

Spinelli Correa, Laurice Mara 09 August 2019 (has links)
The objective of this research is to develop the relationship between starting steps and post newels attached by different connection systems. This research focuses on analyzing solid and box posts connection performance under monotonic and reversed cyclic loads by following European standards EN 26891:1991 and EN 12512:2001, respectively. Moment carrying capacity, stiffness, energy dissipation, and ductility were calculated. Four connection systems were tested, two for solid posts (Sure-Tite™ and Fas-N-Fast™) and two for box posts (L-brackets and wood block with lag bolt). Connections had higher load capacity during the monotonic loading protocol than in the reversed cyclic loading protocol. No strength difference was observed between the solid post connection systems. However, Sure-Tite™ presented a more ductile behavior. For box posts, the L-brackets connection system was superior in strength, while the wood block with lag bolt system had a greater ductile behavior.
3

Examensarbete : Implementering av

Almaliki, Rasha, Kariksiz, Civin January 2007 (has links)
<p>I denna rapport behandlas verktyget FMEA (Failure Mode Effect Analysis), dess användning och genomförande på identifierade komponenter som ingår i elmotorer tillverkade hos ABB LV Motors i Västerås. Målet med detta arbete har varit att ge lärdom om metoden FMEA på företaget för att möjliggöra användandet av verktyget bland medlemmarna på företaget och att vi implementerar verktyget på befintlig motor för att analysera de felsätt som kan uppstå. Eftersom ABB just nu har ett pågående projekt med en ny motor kan våra slutgiltiga felanalyser även ge dem information om vilka ändringar och åtgärder som kan vara till nytta vid utformningen av den nya motorn.</p><p>Efter två veckors praktik i verkstan och en grundlig genomgång av företagets reklamationer kunde vi avgränsa arbetet genom att identifiera de komponenter som analyserna skulle genomföras på. Efter en genomgång tillsammans med våra handledare på företaget kom vi fram till att utföra våra analyser på fem komponenter, två av dem framstod som mycket kritiska som upptäcktes redan vid genomgång av reklamationerna.</p><p>Komponenterna som vi har analyserat är:</p><p>1. Lager</p><p>2. Lindning</p><p>3. Tätning av uttagslåda och uttagslock</p><p>4. Fötter</p><p>5. Sköldar</p><p>Lager som är den näst största kritiska komponent som vi tittat på är en del i motorn som är väldigt känslig, det är viktigt att följa instruktioner för underhåll och smörjning för att undvika för tidiga lagerskador.</p><p>Lindningen är klart den mest kritiska komponenten i våra analyser, detta är för att det är så mycket som spelar in lindningens funktion, koppartrådar, isoleringar, impregnering samt under själva processen kan det uppstå felsätt som påverkar lindningen negativt både direkt men även i ett senare skede då motorn är i drift.</p><p>Tätning av uttagslåda och lock beskriver de felsätt som kan uppstå då tätningen inte är effektiv och tät, vad som kan hända då det kommer in smuts och fukt och hur det eventuellt kan påverka plint eller andra elektriska applikationer. Felanalysen på fötter och sköldar behandlar mycket designfel, toleransfel och hur det påverkar komponenterna.</p><p>I rapporten beskrivs utförligt komponenternas funktioner, processer, underhåll samt det är i princip vad vi har kommit fram till i våra felanalyser fast vi i rapporten beskriver det mer utförligt. Efter beskrivning av varje komponent följer ett FMEA för respektive komponent och de FMEA:n är våra resultat av arbetet, där visas åtskilliga felsätt som är möjliga att uppstå hos varje komponent och även vilka felsätt som är mest kritiska att ta itu med.</p> / <p>In this report we discuss the tool, FMEA (Failure Mode Effect Analysis), we look at its usage and realization on identified components that are included in electrical motors made at ABB LV Motors in Västerås. Our goals with this work have been to give knowledge about the method FMEA to the company so they can learn to use this tool and for us to implement the tool on an existing application to analyze the failures that can occur. Since ABB have a project ongoing with a new motor our analyses can also give them input on what changes and actions to take on the new motor.</p><p>After two weeks training in the workshop and a thorough survey of the companys warranty claims we could define our work by identifying which components we would survey our analyses on. After a run through with our instructors at the company we draw the conclusion to survey our work on five components, which there are two components that are very critical that we discovered during our information collection with the warranty claims.</p><p>The analyzed components are:</p><p>1. Bearing</p><p>2. Winding</p><p>3. Sealing of terminal box and terminal cap.</p><p>4. Motor feet’s</p><p>5. Shields</p><p>Bearing which is after the winding the most critical component, it is a sensitive part and it is very important to follow instructions for maintenance and lubrication to avoid early bearing damages.</p><p>Winding is the clearest most critical component in our analyzes, this is because there is many parts that plays role in the windings function, copper wires, isolations, impregnation and during the process you can have failures that affect the winding in a negative way immediately but also in a later phase when the motor is running.</p><p>Sealing of the terminal box and cap describes those failures that can occur when the sealing is not effective and compact, and what happens is that you get dirt and damp in to the box and how it possibly can affect the connection box and other electrical applications.</p><p>The failure analyze on feets and shields deals with design faults, tolerance faults and how it affects the components.</p><p>In the report we describe the functions of the components, processes, maintenance and that is in general what we have in our FMEA analyses, however in the report we describe it more thoroughly. After the description of every component we have the FMEA of respective component attached. The FMEA analyses are our results in this work, in the analyses we show many possible failures at each component and also which failures are most critical to deal with.</p>
4

Important systems engineering analysis tools : failure mode and effects analysis and hazard analysis

Moore, Alicia Louise Leonard 18 February 2011 (has links)
The goal of every program or project manager is to have a safe reliable product and to have an understanding of the residual risk of operating that product. Two very important systems engineering analysis tools to achieve those objectives are Hazard Analysis and Failure Modes and Effects Analysis. Sometimes seen strictly as Safety and Reliability tasks, these analyses are key to a successful program or project and require input from all stakeholders. When viewed in the Systems Engineering process, Safety and Reliability are truly specialty disciplines within Systems Engineering. Hazard Analysis is used to improve system safety while Failure Modes and Effects Analysis is used to identify ways to increase product reliability; both analyses are required to improve systems design and fully capture the risk for a system or program. Depending on how the analyses are scoped, there could be a perception of overlap and duplication of effort. This paper will present a systems engineering approach to show the need and benefits for performing both types of analyses. Both analysis processes are required to ensure that all possible hazardous conditions and failure modes have been identified and addressed to minimize overall risk to the program/project and to ensure a safe and reliable system. / text
5

Examensarbete : Implementering av

Almaliki, Rasha, Kariksiz, Civin January 2007 (has links)
I denna rapport behandlas verktyget FMEA (Failure Mode Effect Analysis), dess användning och genomförande på identifierade komponenter som ingår i elmotorer tillverkade hos ABB LV Motors i Västerås. Målet med detta arbete har varit att ge lärdom om metoden FMEA på företaget för att möjliggöra användandet av verktyget bland medlemmarna på företaget och att vi implementerar verktyget på befintlig motor för att analysera de felsätt som kan uppstå. Eftersom ABB just nu har ett pågående projekt med en ny motor kan våra slutgiltiga felanalyser även ge dem information om vilka ändringar och åtgärder som kan vara till nytta vid utformningen av den nya motorn. Efter två veckors praktik i verkstan och en grundlig genomgång av företagets reklamationer kunde vi avgränsa arbetet genom att identifiera de komponenter som analyserna skulle genomföras på. Efter en genomgång tillsammans med våra handledare på företaget kom vi fram till att utföra våra analyser på fem komponenter, två av dem framstod som mycket kritiska som upptäcktes redan vid genomgång av reklamationerna. Komponenterna som vi har analyserat är: 1. Lager 2. Lindning 3. Tätning av uttagslåda och uttagslock 4. Fötter 5. Sköldar Lager som är den näst största kritiska komponent som vi tittat på är en del i motorn som är väldigt känslig, det är viktigt att följa instruktioner för underhåll och smörjning för att undvika för tidiga lagerskador. Lindningen är klart den mest kritiska komponenten i våra analyser, detta är för att det är så mycket som spelar in lindningens funktion, koppartrådar, isoleringar, impregnering samt under själva processen kan det uppstå felsätt som påverkar lindningen negativt både direkt men även i ett senare skede då motorn är i drift. Tätning av uttagslåda och lock beskriver de felsätt som kan uppstå då tätningen inte är effektiv och tät, vad som kan hända då det kommer in smuts och fukt och hur det eventuellt kan påverka plint eller andra elektriska applikationer. Felanalysen på fötter och sköldar behandlar mycket designfel, toleransfel och hur det påverkar komponenterna. I rapporten beskrivs utförligt komponenternas funktioner, processer, underhåll samt det är i princip vad vi har kommit fram till i våra felanalyser fast vi i rapporten beskriver det mer utförligt. Efter beskrivning av varje komponent följer ett FMEA för respektive komponent och de FMEA:n är våra resultat av arbetet, där visas åtskilliga felsätt som är möjliga att uppstå hos varje komponent och även vilka felsätt som är mest kritiska att ta itu med. / In this report we discuss the tool, FMEA (Failure Mode Effect Analysis), we look at its usage and realization on identified components that are included in electrical motors made at ABB LV Motors in Västerås. Our goals with this work have been to give knowledge about the method FMEA to the company so they can learn to use this tool and for us to implement the tool on an existing application to analyze the failures that can occur. Since ABB have a project ongoing with a new motor our analyses can also give them input on what changes and actions to take on the new motor. After two weeks training in the workshop and a thorough survey of the companys warranty claims we could define our work by identifying which components we would survey our analyses on. After a run through with our instructors at the company we draw the conclusion to survey our work on five components, which there are two components that are very critical that we discovered during our information collection with the warranty claims. The analyzed components are: 1. Bearing 2. Winding 3. Sealing of terminal box and terminal cap. 4. Motor feet’s 5. Shields Bearing which is after the winding the most critical component, it is a sensitive part and it is very important to follow instructions for maintenance and lubrication to avoid early bearing damages. Winding is the clearest most critical component in our analyzes, this is because there is many parts that plays role in the windings function, copper wires, isolations, impregnation and during the process you can have failures that affect the winding in a negative way immediately but also in a later phase when the motor is running. Sealing of the terminal box and cap describes those failures that can occur when the sealing is not effective and compact, and what happens is that you get dirt and damp in to the box and how it possibly can affect the connection box and other electrical applications. The failure analyze on feets and shields deals with design faults, tolerance faults and how it affects the components. In the report we describe the functions of the components, processes, maintenance and that is in general what we have in our FMEA analyses, however in the report we describe it more thoroughly. After the description of every component we have the FMEA of respective component attached. The FMEA analyses are our results in this work, in the analyses we show many possible failures at each component and also which failures are most critical to deal with.
6

Análise dos modos de falha e efeitos : implementação da metodologia na empresa Sakthi Portugal, SA.

Dias, Ana Luís Morgado 07 March 2013 (has links)
Estágio realizado na Sakthi Portugal, SA, e orientado pela Eng. Helena Coimbra / Tese de mestrado integrado. Engenharia Metalúrgica e de Materiais. Universidade do Porto. Faculdade de Engenharia. 2010
7

Hybrid decision support system for risk criticality assessment and risk analysis

Abdelgawad, Mohamed Abdelrahman Mohamed Unknown Date
No description available.
8

Hybrid decision support system for risk criticality assessment and risk analysis

Abdelgawad, Mohamed Abdelrahman Mohamed 06 1900 (has links)
Risk management is essential for the construction industry to successfully fulfill project objectives. Several studies were conducted in the past decade to support quantitative risk analysis. These studies were based on using some of the commonly used techniques such as risk matrix, decision trees, Monte Carlo, and sensitivity analysis. However, some of these techniques are limited because they either do not support quantitative risk analysis, or are difficult to be utilized due to the required amount of data to support quantitative risk analysis. To address such limitations, a comprehensive framework was developed, based on combining three well-known techniques in reliability engineering, i.e., failure mode and effect analysis, fault trees, and event trees with fuzzy logic. Fuzzy logic and failure mode and effect analysis were first combined to provide an answer to the problem of identifying of critical risk events through the development of a fuzzy expert system software package named Risk Criticality Analyzer. To support quantitative risk analysis in the construction industry, fault tree and event tree were combined, and fuzzy logic is used to solve both of them. Fuzzy arithmetic operations on fuzzy numbers were used to represent logical gates in the fault tree structure, and to conduct event tree analysis. To automate solving both fault trees and event trees, Fuzzy Reliability Analyzer was designed and implemented using Visual Basic.net. Both tools were then validated through case studies. The results indicate that by using the proposed methodology, the risk can be assessed effectively and efficiently. The proposed framework presented in this research provides the contribution of combining fuzzy logic with failure mode and effect analysis, fault trees, and event trees in a comprehensive framework to support risk identification, risk assessment, and risk response. Since the proposed framework is based on using linguistic terms, risk analysts are offered a more convenient and practical framework to conduct risk analysis. The proposed framework was able to address several limitations attributed to the conventional application of failure mode and effect analysis and offered a generic framework that can be adapted to fit any industry or organization. / Construction Engineering and Management
9

Analise de perigos e pontos criticos de controle para alimentos irradiados no Brasil

BOARATTI, MARIA de F.G. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:49:40Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:21Z (GMT). No. of bitstreams: 1 10192.pdf: 6833898 bytes, checksum: 366c211ea17c52eecbc22d5392203f97 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
10

A New Approach to Groundwater Remediation Treatability Studies - Moving Flow-through Column Experiments from Laboratory to In Situ Operation

January 2013 (has links)
abstract: In situ remediation of contaminated aquifers, specifically in situ bioremediation (ISB), has gained popularity over pump-and-treat operations. It represents a more sustainable approach that can also achieve complete mineralization of contaminants in the subsurface. However, the subsurface reality is very complex, characterized by hydrodynamic groundwater movement, geological heterogeneity, and mass-transfer phenomena governing contaminant transport and bioavailability. These phenomena cannot be properly studied using commonly conducted laboratory batch microcosms lacking realistic representation of the processes named above. Instead, relevant processes are better understood by using flow-through systems (sediment columns). However, flow-through column studies are typically conducted without replicates. Due to additional sources of variability (e.g., flow rate variation between columns and over time), column studies are expected to be less reproducible than simple batch microcosms. This was assessed through a comprehensive statistical analysis of results from multiple batch and column studies. Anaerobic microbial biotransformations of trichloroethene and of perchlorate were chosen as case studies. Results revealed that no statistically significant differences were found between reproducibility of batch and column studies. It has further been recognized that laboratory studies cannot accurately reproduce many phenomena encountered in the field. To overcome this limitation, a down-hole diagnostic device (in situ microcosm array - ISMA) was developed, that enables the autonomous operation of replicate flow-through sediment columns in a realistic aquifer setting. Computer-aided design (CAD), rapid prototyping, and computer numerical control (CNC) machining were used to create a tubular device enabling practitioners to conduct conventional sediment column studies in situ. A case study where two remediation strategies, monitored natural attenuation and bioaugmentation with concomitant biostimulation, were evaluated in the laboratory and in situ at a perchlorate-contaminated site. Findings demonstrate the feasibility of evaluating anaerobic bioremediation in a moderately aerobic aquifer. They further highlight the possibility of mimicking in situ remediation strategies on the small-scale in situ. The ISMA is the first device offering autonomous in situ operation of conventional flow-through sediment microcosms and producing statistically significant data through the use of multiple replicates. With its sustainable approach to treatability testing and data gathering, the ISMA represents a versatile addition to the toolbox of scientists and engineers. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2013

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