Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007. / Bruce R. Ellingwood, Committee Chair ; Abdul-Hamid Zureick, Committee Member ; James I. Craig, Committee Member ; Reginald DesRoches, Committee Member ; Kenneth M. Will, Committee Member.

Wear debris found in gear lubricating oil provides extremely valuable information on the nature and severity of gear faults as well as remaining gear life. The conventional off-line process of taking samples of oil for testing of wear debris is a hindrance because it is laborious, expensive, delays information collection, and is expert oriented. In view of these limitations, the development of automating wear debris particle analysis using various approaches has been ongoing for years. However, existing online technology does not encourage widespread use of wear debris analysis (WDA) in the industry. High costs coupled with expert and labour requirements have led users to use other types of condition-based maintenance, such as vibration. There is a need to develop a WDA technique that is relatively cheap, online, requires little expertise to handle, and provides more information for maintenance decision-making. This PhD thesis proposes a WDA technique which uses image processing and three-dimensional image reconstruction to diagnose the health of machinery. Its emphasis is on using the thickness and volume of the particles generated over time to predict the onset of gearbox failure, so that maintenance action can be taken before gears reach catastrophic failure.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / The surprise failure of two NASA Space Shuttles and the premature failures of satellite subsystem equipment on NASA satellites are motivating NASA to adopt an engineering discipline that uses telemetry specifically developed for preventing surprise equipment failures. The NASA Orion spacecraft is an Apollo module-like capsule planned to replace the NASA Space Shuttle reusable launch vehicle for getting astronauts to space and return to the earth safely as well as a crew escape vehicle stored at the ISS. To do so, NASA is adopting a non-Markov reliability paradigm for measuring equipment life based on the prognostic and health management program on the Air Force F-35 Joint Strike Fighter. The decision is based on the results from the prognostic analysis completed on the Space Shuttle Challenger and Columbia that identified the information that was present but was ignored for a variety of reasons. The goal of a PHM is to produce equipment that will not fail prematurely. It includes using predictive algorithms to measure equipment usable life. Equipment with transient behavior caused from accelerated of parts will fail prematurely with 100% certainty. For many decades, it was believed that test equipment and software used to in testing and noise from communications equipment were the cause of most transient behavior. With the processing speed of today's processors, transient behavior is caused from at least one part suffering from accelerated aging. Transient behavior is illustrated in equipment telemetry in a prognostic analysis. Telemetry is equipment performance information and equipment performance has been used to increase reliability, but performance is unrelated to equipment remaining usable life and so equipment should be failing prematurely. A PHM requires equipment telemetry for analysis and so analog telemetry will be available from all Orion avionics equipment. Replacing equipment with a measured remaining usable life of less than one year will stop the premature and surprise equipment failures from occurring during future manned and unmanned space missions.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Satellite and launch vehicles continues to suffer from catastrophic infant mortality failures. NASA now requires satellite suppliers to provide on-orbit satellite delivery and a free satellite and launch vehicle in the event of a catastrophic infant mortality failure. A high infant mortality failure rate demonstrates that the factory acceptance test program alone is inadequate for producing 100% reliability space vehicle equipment. This inadequacy is caused from personnel only measuring equipment performance during ATP and performance is unrelated to reliability. Prognostic technology uses pro-active diagnostics, active reasoning and proprietary algorithms that illustrate deterministic data for prognosticians to identify piece-parts, components and assemblies that will fail within the first year of use allowing this equipment to be repaired or replaced while still on the ground. Prognostic technology prevents equipment failures and so is pro-active. Adding prognostic technology will identify all unreliable equipment prior to shipment to the launch pad producing 100% reliable equipment and will eliminate launch failures, launch pad delays, on-orbit infant mortalities, surprise in-orbit failures. Moving to the 100% reliable equipment extends on-orbit equipment usable life.

ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / The surprise failure of two NASA Space Shuttles and the premature failures of satellite subsystem equipment on NASA satellites are motivating NASA to adopt an engineering discipline specifically developed for preventing surprise equipment failures. The NASA Orion spacecraft is an Apollo module-like capsule planned to replace the NASA Space Shuttle reusable launch vehicle for getting astronauts to space and return to the earth safely as well as a crew escape vehicle stored at the ISS. To do so, NASA is adopting a non-Markov reliability paradigm for measuring equipment life based on the prognostic and health management program on the Air Force F-35 Joint Strike Fighter. The decision is based on the results from the prognostic analysis completed on the Space Shuttle Challenger and Columbia that identified the information that was present but was ignored for a variety of reasons prior to both accidents. The goal of a PHM is to produce equipment that will not fail prematurely and includes using predictive algorithms to measure equipment usable life. Equipment with transient behavior, missed by engineering analysis is caused from accelerated of parts will fail prematurely with 100% certainty. With the processing speed of today's processors, transient behavior is caused from at least one part suffering from accelerated aging. Transient behavior is illustrated in equipment telemetry in a prognostic analysis but not in an engineering analysis. Telemetry is equipment performance information and equipment performance has been used to increase reliability, but performance is unrelated to equipment remaining usable life and so equipment should be failing prematurely. A PHM requires equipment telemetry for analysis and so analog telemetry will be available from all Orion avionics equipment. Replacing equipment with a measured remaining usable life of less than one year will stop the premature and surprise equipment failures from occurring during future manned and unmanned space missions.

In future cities, urban drainage and flood management systems should be designed not only to reliable during normal operating conditions but also to be resilient to exceptional threats that lead to catastrophic failure impacts and consequences. Resilience can potentially be built into urban drainage systems by implementing a range of strategies, for example by embedding redundancy and flexibility in system design or rehabilitation to increase their ability to efficiently maintain acceptable customer flood protection service levels during and after occurrence of failure or through installation of equipment that enhances customer preparedness for extreme events or service disruptions. However, operationalisation of resilience in urban flood management is still constrained by lack of suitable quantitative evaluation methods. Existing hydraulic reliability-based approaches tend to focus on quantifying functional failure caused by extreme rainfall or increases in dry weather flows that lead to hydraulic overloading of the system. Such approaches take a narrow view of functional resilience and fail to explore the full system failure scenario space due to exclusion of internal system failures such as equipment malfunction, sewer (link) collapse and blockage that also contribute significantly to urban flooding. In this research, a new analytical approach based on Global Resilience Analysis (GRA) is investigated and applied to systematically evaluate the performance of an urban drainage system (UDS) when subjected to a wide range of both functional and structural failure scenarios resulting from extreme rainfall and pseudo random cumulative link failure respectively. Failure envelopes, which represent the resulting loss of system functionality (impacts) are determined by computing the upper and lower limits of the simulation results for total flood volume (failure magnitude) and average flood duration (failure duration) at each considered failure level. A new resilience index is developed and applied to link resulting loss of functionality magnitude and duration to system residual functionality (head room) at each considered failure level. With this approach, resilience has been tested and characterized for a synthetic UDS and for an existing UDS in Kampala city, Uganda. In addition, the approach has been applied to quantify the impact of interventions (adaptation strategies) on enhancement of global UDS resilience to flooding. The developed GRA method provides a systematic and computationally efficient approach that enables evaluation of whole system resilience, where resilience concerns ‘beyond failure’ magnitude and duration, without prior knowledge of threat occurrence probabilities. The study results obtained by applying the developed method to the case studies suggest that by embedding the cost of failure in resilience-based evaluation, adaptation strategies which enhance system flexibility properties such as distributed storage and improved asset management are more cost-effective over the service life of UDSs.

Made available in DSpace on 2015-04-22T22:11:17Z (GMT). No. of bitstreams: 1 Marcu_Aurelio.pdf: 6856454 bytes, checksum: 8b0130e36bdbeac8f01f349628863ece (MD5) Previous issue date: 2011-12-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This research addresses the Products Development Process - (PDP) adopted in manufacturing companies of artifacts for mobile communication (cellular), installed in Manaus Industrial Pole (MIP), the research is focused on how companies deal with the introduction of a new product on the market and which information is to be used to improve its process and products. The work refers to the flow of information used in the process of introduction and analysis of failures of the products, in particular in relation to the monitoring process for new products, currently used in 02 (two) multinational companies. It raised issues regarding the monitoring of the quality of their products recently launched in the market and which analytical techniques are adopted, and the comprehensiveness of the same, as well as how the information reaches the department of new products, in each organization. This is a case study involving the processes of monitoring and analysis of failures in products on the market, and comparing the processes used in the surveyed companies, pointing out the main elements and contribution to the PDP model, as well as the strengths and weaknesses in each case. As a conclusion to the work, a theoretical model of information management as a complement to the current PDP model is presented, considering the experience acquired in 08 (eight) years of work in the areas of testing and analysis of failures in products and in the department of development of new products and software development. / O presente trabalho de pesquisa verse sobre o Processo de Desenvolvimento de Produtos (PDP) adotado em empresas manufatureiras de artefatos de comunicação móvel (celulares), instaladas no Pólo Industrial de Manaus (PIM), a pesquisa esta focada em como as empresas lidam com a introdução de um novo produto no mercado e quais informações são utilizadas para melhorias em seus processo e produtos. O trabalho refere-se ao fluxo de informações adotado no processo de introdução e analise de falhas dos produtos, em especial no que se refere ao processo de acompanhamento de novos produtos, atualmente utilizado nas 02 (duas) empresas multinacionais. Foram focados aspectos quanto ao monitoramento da qualidade de seus produtos recém lançados no mercado e quais técnicas de analise são adotadas e a abrangência das mesmas, assim como a informação chega ao departamento de novos produtos, em cada organização. Trata-se de um estudo de caso envolvendo os processos de acompanhamento e análise de falhas em produtos no mercado, comparando os processos utilizados nas empresas pesquisadas, apontando os principais elementos e contribuição para o modelo PDP, assim como os pontos fortes e fracos em cada processo. Como conclusão do trabalho, é apresentado um modelo teórico de gestão da informação como complemento ao atual modelo PDP, considerando-se a experiência adquirida em 08 (oito) anos de trabalho nas áreas de teste e analise de falhas em produtos e no departamento de desenvolvimento de novos produtos e desenvolvimento de software.