A metallurgical study of aluminium alloys used as aircraft components

The effects of heat treatment on morphologies and microstructures of Al 2024 and Al 7050 alloys, used as aircraft components, were studied by metallographic techniques. Light microscopy (LM) and quantitative image analysis were used to characterize the precipitate dispersion and morphology for these alloys. The application of the scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) combined techniques for studying these multiphase systems makes it possible to distinguish and quantify the different phases in the surface structure. Xray diffraction also permitted a qualitative comparison of the structures before and after heat treatments.

Aircraft interior failure pattern recognition utilizing text mining and neural networks

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aircraft accident in Brazil: Boeing vs. Legacy?

Air accidents represent a small proportion of the flights registered worldwide. Airplane collisions in the air are rare. In September of 2006, a Boeing 737-800 collided in midair with a Legacy Jet. It was the largest accident registered in the history of Brazilian aviation until that time. The present study explores aspects of press coverage of the accident. Data and information reported in the media about the accident from September 2006 to August 2007 were collected and discussed. Media coverage called attention to two unusual aspects: politicisation of the discussion, culminating in the opening of congressional inquiries, and equally the concomitance of police investigations interfering in the work of agencies responsible for the official accident investigation. Emphasis on assigning guilt and establishing penalties may close the windows of opportunity an accident had opened for discussions on the improvement of air safety. In Brazil, political imperatives and organizational pressures have interfered and the possibilities of organizational learning from the accident have been drastically curtailed.

A review on the development and properties of continuous fiber/epoxy/aluminum hybrid composites for aircraft structures

Weight reduction and improved damage tolerance characteristics were the prime drivers to develop new family of materials for the aerospace/ aeronautical industry. Aiming this objective, a new lightweight Fiber/ Metal Laminate (FML) has been developed. The combination of metal and polymer composite laminates can create a synergistic effect on many properties. The mechanical properties of FML shows improvements over the properties of both aluminum alloys and composite materials individually. Due to their excellent properties, FML are being used as fuselage skin structures of the next generation commercial aircrafts. One of the advantages of FML when compared with conventional carbon fiber/epoxy composites is the low moisture absorption. The moisture absorption in FML composites is slower when compared with polymer composites, even under the relatively harsh conditions, due to the barrier of the aluminum outer layers. Due to this favorable atmosphere, recently big companies such as EMBRAER, Aerospatiale, Boing, Airbus, and so one, starting to work with this kind of materials as an alternative to save money and to guarantee the security of their aircrafts.

Development of a model to measure the efficiency of outsourced companies in the process of aircraft spare parts technical publications

This paper presents a proposal of a model to measure the efficiency of outsourced companies in the aeronautical industry applying the methods DEA and AHP. It also proposes an evaluation in the relation between the variables of the process and the value obtained for the effiiency. The criteria of Quality, Time and Cost were considered the outputs of the process, and those criteria were quantified by AHP for DEA matrix.The number of technical documents received by those outsorced companies were considered the input of the process. The other purpose is to separate the companies in groups considered able to receive an investment to improve their process. Copyright © 2008 SAE International.

Monitoramento e avaliação da condição de um sistema propulsor aeronaútico através de técnicas de análise de partículas em óleos lubrificantes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

SVET, SKP and EIS study of the corrosion behaviour of high strength Al and Al-Li alloys used in aircraft fabrication

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of the nonlinear behavior of a F-16 aircraft using discrete-time Volterra series

The linearity assumption in the structural dynamics analysis is a severe practical limitation. Further, in the investigation of mechanisms presented in fighter aircrafts, as for instance aeroelastic nonlinearity, friction or gaps in wing-load-payload mounting interfaces, is mandatory to use a nonlinear analysis technique. Among different approaches that can be used to this matter, the Volterra theory is an interesting strategy, since it is a generalization of the linear convolution. It represents the response of a nonlinear system as a sum of linear and nonlinear components. Thus, this paper aims to use the discrete-time version of Volterra series expanded with Kautz filters to characterize the nonlinear dynamics of a F-16 aircraft. To illustrate the approach, it is identified and characterized a non-parametric model using the data obtained during a ground vibration test performed in a F-16 wing-to-payload mounting interfaces. Several amplitude inputs applied in two shakers are used to show softening nonlinearities presented in the acceleration data. The results obtained in the analysis have shown the capability of the Volterra series to give some insight about the nonlinear dynamics of the F-16 mounting interfaces. The biggest advantage of this approach is to separate the linear and nonlinear contributions through the multiple convolutions through the Volterra kernels.

Aircraft selection with DEA's triple index: an approach for sustainability

The objective of this paper is to present a benefit-cost ranking of 127 civil transport aircraft; this ranking was determined considering a new data envelopment analysis (DEA) approach, called triple index, which combines three assessment methods: 1) standard frontier, 2) inverted index; 3) cross-multiplicative index. The analysis used the following inputs: a) market price; b) direct operating costs; and as outputs: a) payload, b) cruise speed; c) maximum rate of climb with a single engine. To ensure the homogeneity of the units, the aircrafts were divided according to the propulsion system (jet and turboprop) and size (regional, narrow-body and wide-body); they were also evaluated according to different ranges in order to identify the aircraft with the best cost-benefit relationship for each option.

Depósitos de calda obtidos com a aplicação aérea de defensivos na cultura da banana

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A produção da subjetividade no contexto institucional de um seminário católico

Esta pesquisa visa estudar a produção da subjetividade no contexto institucional de um Seminário Católico. Este estabelecimento funciona em regime de internato no qual atualmente 70 seminaristas estudam Filosofia durante 3 anos, numa etapa preparatória para o sacerdócio. Pesquisamos o funcionamento da vida institucional através da observação participante e utilizamos entrevistas semi-estruturadas para entender como o seminarista experiencia sua vida. Os resultados preliminares indicam que a vida no contexto institucional do Seminário produz diversas modalizações da subjetividade nos seminaristas internados no estabelecimento: há uma perda considerável de autonomia pessoal, da liberdade de ir e vir, agir e decidir, originando comportamentos de dependência excessiva, de resistência à mudança, de conversão ao papel proposto, de rivalidade fraterna. A contradição detectada entre o aparelho repressivo e o discurso participativo parece produzir nos indivíduos características marcadas pela clivagem e pela recusa.

O internato escolar O Ateneu: produção de subjetividade na instituição total

Dans cet article on cherche à identifier les effets de l'institutionnalisation dans la production de la subjectivité dans un établissement scolaire total. La recherche est basée sur le roman «O Ateneu » de Raul Pompeia, analysé à partir de la théorie de Goffman (1961-1987) relative aux institutions totales. on décrit l itinéraire moral que le personnage Sergio développe, à son entrée à l'internat, évoquant les vicissitudes par lesquelles il passe dans ce contexte institutionnel : période d'adaptation, crises évolutives, initiations sexuelles, problèmes de rivalités, etc. les établissements totaux semblent s'organiser d'une façon caractéristique et fonctionner de manière autonome. on pourra comprendre les problèmes sociaux et les effets sur la subjectivité produite par les institutions totales par l étude des relations de pouvoir subjacentes à ces types d'établissements. Le temps pendant lequel un individu vit comme interné peut laisser des marques profondes dans sa subjectivité et se configure comme un thème personnel approprié.

O internato escolar como instituição total: violência e subjetividade

Neste artigo, apresentamos um caso da literatura relativo ao internato escolar por meio do qual exemplificamos e discutimos alguns aspectos da violência e subjetividade na instituição total. Utilizamos as análises de Goffman sobre as instituições totais e algumas hipóteses psicanalíticas a respeito da agressividade para a leitura de O Jovem Törless , de Robert Musil. Instituições totais parecem ultrapassadas, mas elas persistem na atualidade: FEBENS, asilos, orfanatos, conventos, prisões, quartéis, manicômios, seminários para formação de padres, etc. Nossa pesquisa visa ao desvelamento do modo de funcionamento dessas instituições e a explicitação de seus efeitos na produção da subjetividade daqueles que delas participam. Concluímos que no paralelo que podemos estabelecer entre os fins educativos do internato escolar e os objetivos terapêutico-correcionais do hospital psiquiátrico e da prisão, existe mais do que uma simples analogia.

Estudo psicossocial de um seminário teológico: a formação do clero católico em análise

Este artigo apresenta dados preliminares e discussões de uma investigação em psicologia social sobre a produção da subjetividade eclesiástica. Utilizando o instrumental teórico da análise institucional, estudamos o dispositivo pedagógico seminário. Nosso campo de pesquisa é um seminário católico de teologia, onde vivem 50 seminaristas em regime de internato, na etapa final de preparação para o sacerdócio, os quais, uma vez ordenados, passarão a ocupar posições de relevância que consistem na coordenação de comunidades paroquiais amplas. Os dados foram obtidos por meio da observação do cotidiano institucional. Apresentamos algumas conclusões preliminares. Encontramos fortes contradições entre os discursos oficiais e as práticas cotidianas no seminário teológico.

Qualitative and quantitative characterization of aluminium alloys after corrosion testing

The 2024 and 7050 aluminium alloys used as aircraft components were subjected to laboratory corrosion tests in sodium chloride solution, Light-microscope examinations make it possible to characterise morphological aspects of the localised corrosion. Image analysis was used to determine both depth and width of pits over corroded surfaces. It has been concluded that the annealing could reduce the pit growth in both alloys, by means of grains recrystallization or recovery. The 2024 alloy also tends to present an exfoliation mechanism, mainly throughout non-recrystallized and recrystallized grain boundaries, increasing the width and sustaining the depth of pit cavities during exposition to saline atmosphere. SEM and EDS analysis reveal the morphology and elemental distribution of the corrosion products formed after immersion corrosion test. Some of these products were identified by X-ray diffraction analysis. For 2024, Al(OH)(3), MS(OH)(2) and Cu2O were found. AI(OH)(3) and Cu2O were also found in 7050 samples.