Desenvolvimento e aplicação da instrumentação virtual na unidade móvel de ensaios na barra de tração - UMEB

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Desenvolvimento de um tribômetro, tipo cilindro sob disco, para ensaios tribológicos em formulações com óleos vegetais

Pós-graduação em Engenharia Mecânica - FEIS

Comparação entre valores de ensaios experimentais e calculados da resistência ao embutimento da madeira de Pinus taeda L.

To design connections between timber parts with metal dowels (nails or bolts), two phenomena must be considered: bending of the metal dowel and the embedment strength in the wood. The Brazilian Standard ABNT NBR 7190:1997 proposes the methods used in the laboratory tests to determine the embedment strength with the metal dowell and, in the absence of testing, specifies relations to calculate the embedment strength from the compression strength. The aim of this research was to compare the embedment strength values obtained by experimental tests and calculated by the relationships established by the Brazilian Standard ABNT NBR 7190:1997. By the results of the hypothesis tests, it was possible to conclude that the estimate of the embedment strength parallel to the grain proposed by the Brazilian standard ABNT NBR 7190:1997, establishing equivalence with the strength compression results in the same direction, must be effective to the wood species Pinus taeda L., however, the same was not found in the perpendicular direction with respect to the grain, possibly explained by the alpha(e) values in the equation to calculed fe(90)

Paulo Prado e a Semana de Arte Moderna: ensaios e correspondências

Pós-graduação em Letras - FCLAS

Atenuação dos níveis de ruídos em tratores agrícolas

Esta pesquisa analisou as diversas soluções para atenuar os níveis de ruído dos tratores e propor um projeto de redução do ruído na sua fonte. Para tal, se propôs projetar, executar e testar alterações em componentes mecânicos causadores de ruído nos tratores, fazendo com que esses níveis se enquadrem em valores considerados salubres. Todas alterações e ensaios foram executados num trator Massey Ferguson MF 290. Para a redução do ruído foram atacados as 3 fontes principais de ruído do trator : o sistema de exaustão de gases, a hélice do sistema de arrefecimento e o sistema de admissão de ar. Como conclusão final pode-se afirmar que é possível atenuar o ruído de tratores agrícolas até níveis salubres (que não causem perda de audição a seus operadores), atuando-se exclusivamente nas fontes de ruído (motor e seus acessórios).

Aproveitamento de resíduos de laminação da madeira para a produção de painel estrutural

Products derived from wood or engineered products are becoming interesting alternatives to the replacement of solid wood in various applications, from structural components to the furniture industry and packaging. Among these products, there are panels built by strands, particles and fibers, each one having their particular characteristics and potential of use. Since the different types of panels are produced, waste generation is part of the process, and that more technological it is, it still generates losses of raw materials. Based on the need for rational use of raw materials and using almost full of industrially processed wood, It arises the proposal of this work, which seeks to use waste from the lamination, like pieces of strands, broken strands, strands rough, cracked strands to produce panels with structural characteristics of the OSL panel (Oriented Strand Lumber), LSL (Laminated Strand Lumber) and OSB (Oriented Strand Lumber). Besides the use of waste, this paper seeks an alternative to the use of the adhesive, because the industry uses formaldehyde-based adhesives, which over the press, they emit large amounts of formaldehyde, which is very aggressive to humans and environment. The panels made with polyurethane resin based on castor oil and hot-pressed were characterized by physical and mechanical tests according to specifications of European Standard (EN). High values of tensile strength, elastic modulus and density were found in the results of tests. Adding to stable values of swelling and moisture content, the panel studied adds attractive features to the panel market, especially in the civil construction

Ensaios não destrutivos: metrologia e calibração

To perform the quality control of various industries like: petrochemical, nuclear, aerospace, steel, shipbuilding, pulp and paper, and inspection of welded products, castings, forgings, rolled products, among others, used the method of Non-Destructive Testing (NDT). The method is based on the physical properties of the material, so selecting a procedure more appropriate. The company Inter-Metro Serviços Especiais Ltda., with its cutting-edge laboratory, dedicated to the implementation of calibration services and measurement equipment for industrial, medical, occupational safety and Non-Destructive Testing (NDT). It has a trained team, providing guidance and providing support for improving procedures for testing and measuring

Estudo e aplicação da técnica de vibroacustografia em ensaios não destrutivos

A presença de falhas, trincas, furos e fadigas causam perturbações nos modos vibracionais (normais) de uma estrutura, por exemplo, tubos, gasodutos e peças metálicas. Uma vez conhecido o espectro de freqüência de uma estrutura instalada em condições normais (sem falhas), é possível acompanhar através, de ensaios não destrutivos uma alteração no espectro de freqüência que pode estar associado a alguma falha mecânica na estrutura.O presente trabalho busca encontrar um padrão nos sinais de resposta dos materiais analisados pela técnica de Vibroacustografia, antes e depois das deformidades causadas. Tentando viabilizar a técnica para a utilização em Ensaios Não Destrutivos (END). E futuramente, para as amostras biológicas, espera-se estender os conhecimentos obtidos dos ensaios anteriores para detecção e prevenção de possíveis fraturas do tecido ósseo

Comissionamento de turbinas hidráulicas: ensaios de faixa operativa, índex, test e rejeição de carga

With growing electricty demand, the importance of generation through hydropower, a renewable energy source, it’s of great importance. This demand derives from the country’s growth, as well as events that will occur in the coming years. The commission has a crucial role before the entry into operation of hydroelectric plant, sice, ensures a good operation of hydraulic and electrical systems, as well as the safety of the installation. This paper is a case study, commissioning in a PCH in especially the most important tests, such as range operation, índex tes and load rejection. In these trials we can get a Idea of the actual behavior of the unit, as well as future operation maneuvers, and evidence of real efficiency

Estudo comparativo de dois tipos de painéis de MDP: com adição de papel impregnado e lâminas de bambu

This work is the production of two types of particle boards reconstructed MDP (Medium Density Particleboard), the first with the addition, in the inner layer of particles of impregnated paper, the ratios of 0%, 1%, 5% and 20 %. In the second type of panel MDP was inserted with blades of bamboo species Dendrocalumus giganteus as coatings and structural reinforcement. The MDP panel, used as a basis for both cases has the composition of three layers, two external particles with smaller particle size and an inner layer composed of particles of larger particle sizes. Assays were performed based on physical and mechanical NBR 14.810/2006 for the determination of the board density, thickness swelling, water absorption, moisture content, bending, tension parallel and perpendicular, and testing of particle sizes of the particles did not exists in standard references. The results were analyzed and compared the results of the commercial boards made from 100% eucalyptus, based on the limits specified by the ABNT NBR 14.810/2006. The values of the tests showed similar results indicating normative specifications in a positive way, the possibility of production of MDP with the use of waste paper impregnated. As for the panel with bamboo blades, the tests showed a mechanical performance far superior to MDP market, explaining the study and possible implementation of the bamboo for use where the MDP will suffer greater mechanical stress, such as doors, tops and benches tables

Análise estatística da vida em fadiga de compósitos estruturais pela distribuição de Weibull

Nowadays technological trend is based on finding materials that could support low weight with satisfactory mechanical properties and for this reason composite material became a very attractive topic in research projects all over the world. Due to its heterogenic properties, this type of material shows scatter in mechanical test results, especially in cyclic loading. Therefore it is important to predict its fatigue strength behaviour by statistic analysis, once fatigue causes approximately 90% of the failure in structural components. The present work aimed to investigate the fatigue behaviour of the Twill/Cycom 890 composite, which is carbon fiber reinforced with polymeric resin as matrix and manufactured via RTM process (Resin Transfer Molding). All samples were tested in different tensile level in triplicate in order to associate these values. The statistical analysis was conducted with Two-Parameter Weibull Distribution and then evaluated the fatigue life results for the composite. Weibull graphics were used to determine the scale and shape parameters. The S-N curve for the Twill/Cycom composite was drawn and indicated the number of cycles to occur the first damages in this material. The probability of failure was associated with material reliability, as shown in graphics for the different tensile levels and fatigue life. In addition, the laminate was evaluated by ultrasonic inspection showing a regular impregnation. The fractographic analysis conducted by SEM showed failure mechanisms for polymeric composites associated to cyclic loadings ... (Complete abstract click electronic access below)

Abordagem scrum de gerenciamento ágil para desenvolvimento de novos produtos aplicada a área de ensaios de uma fabricante de aeronaves

There are many approaches and techniques about Administration and Management of Projects in order to provide greater agility, efficiency and transparency during the development process of new products. Simultaneously, a pursuit for a management approach more flexible in its planning and strategic changes during the development campaign, such as, comprehend the project's unpredictability level and deal it by monitoring and estimates tools. These features tend to accentuate itself in manufacturers of complex products, as aircraft and other aerospace technologies. By these conditions thus research aims to describe a case when the Agile Management Processing of Project Development Scrum was used in the Test area of an aircraft manufacturer. Focused on the Scrum implementation over the area, its adaptation, evolution and achievements the research proposes to analyze the improvements, indicate the obstacles and discuss solutions, contributing then to the theoretical basis of the considered theme and futures updates applicable to the area. The research is classified as qualitative; furthermore the information and data analyzed were obtained by interviews with professionals and observations of the processes from the major aircraft manufacturer

Proposta de conector para ensaios de ligações CDE submetidas à tração perpendicular as fibras em madeira de pinus

The growth of urban population associated with the shortage of supply of public infrastructure such as hospitals, kindergartens, schools, among others, has reinforced the need to develop alternative methods that simplify the construction processes and allows for a reduction in these costs works. The conventional processes have increasingly been shown ineffective to solve the problem of demand for different types of urban and rural buildings. Given this fact, industrial construction processes can gain space and have proven to be highly interesting to solve the above problems, in particular, considering the cost-effective and time. Therefore, this study aimed to determine the influence of moisture on the strength of metal plate connections connectors (printed plate with teeth). For the sizing of the links between structural lumber using metal connectors with teeth prints; controlled process variables (drying of the wood and the different moisture contents), and finally found results and compare them with different literatures order to obtain a qualitative efficiency of the process. Some specimens had very low expectations, can be explained by the presence of bone marrow, and pre-existing cracks. Thus, the results were discarded for further analysis and more accurate results

Desenvolvimento e caracterização de sistemas líquido-cristalinos para aplicação tópica de metotrexato: estudo da bioadesão e ensaios biológicos in vitro

A psoríase é uma doença inflamatória relativamente comum da pele e das articulações, podendo se tornar crônica. Nos últimos anos, a expansão do arsenal terapêutico para o paciente com psoríase tem permitido aos médicos combaterem, de forma mais agressiva, a patogênese da doença. Um fármaco utilizado para o tratamento é o metotrexato, que, apesar de ser bastante eficaz, possui potencial para a toxicidade sistêmica, como toxicidade hematológica, hepática e pulmonar. Sendo assim, muita atenção tem sido dada ao desenvolvimento de novos veículos com o objetivo não só de aumentar a eficácia terapêutica de substâncias ativas, como também de permitir a redução da sua dose total necessária, minimizando os efeitos colaterais tóxicos. Os cristais-líquidos são sistemas promissores para aplicação tópica, pois promovem liberação controlada de fármacos, contribuindo para amenizar efeitos adversos, por exemplo, do metotrexato. Uma vez que há possibilidade de as substâncias incorporadas em formulações tópicas serem absorvidas pela pele e mucosas, existe a necessidade de garantir que as formulações sejam seguras. Este trabalho teve o objetivo de avaliar a bioadesão e a citotoxicidade in vitro de três sistemas líquido-cristalinos contendo metotrexato para o tratamento da psoríase. Resultados de bioadesão revelaram que as três formulações analisadas apresentaram forças bioadesivas próximas, sendo o sistema A mais bioadesivo. Com relação a estudos de reologia, houve comportamento de fluido não-newtoniano, pseudoplástico e tixotrópico. Além disso, a adição de metotrexato à formulação A, aumentou a viscosidade do sistema. Ensaios de citotoxicidade sugerem a possibilidade de liberação prolongada de metotrexato, contribuindo para o aumento da viabilidade celular

Estudo de causas de falhas em selos mecânicos de bombas centrífugas para circulação de óleo térmico

This study is about a heating line that uses thermal oil. It is located in a facility that produces interlayers used in cars windshields. A plastic resin is melted and is sent to a matrix called DIE where the interlayers are produced. The DIE needs to receive heat from the circulation of thermal oil in four different regions of its interior, to ensure the correct thickness of the interlayer. The thermal energy is provided by electric heaters and the flow of thermal oil is impelled by four mechanically sealed centrifugal pumps (one per region). The key point of this study is the fact that these four pumps of the system have reported successive failures in the mechanical seals. Apparently, a poorly designed project has burdened the system intermittently. The pumps operation condition is located in a region of low efficiency, according to the characteristic curves. This fact is the source of the noticeable reduced time between failures. Changes in the configuration of the facility and in the number of pumps will be proposed, aiming to achieve higher operational efficiency. The proposals will be mathematically analyzed according to the Hydraulic Institute criteria. At the same time, we will also keep focus on an in-depth study of a heating system structure, starting with a detailed approach for each component and discussion about its real need and economic viability. At the end of this paper it is shown that the gain in efficiency achieved with the new proposed configuration reflects not only in the reduction of maintenance costs, but also a potential improvement in energy efficiency. It is shown that these two aspects are closely related and together form the basis for the design of a reliable and efficient pumping system