Analise de defeitos em motores através de vibração mecânica: estudo de caso

Revolving machines are among the most used equipment in general industry and therefore expenditures on this equipment class are a significant portion of the total amount spent by the company. If there is an unscheduled stop of some of this equipment, industrial plants can lose huge amounts of money caused by interrupted production and parts delay. Others may increase significantly maintenance costs due to consequences elsewhere not affected before. Even plant and people safety can be in danger if there is an operation interruption without a backup system start. This work is focused on a rotating system case study which is monitored by vibration analysis that shows that is possible to determine when is the most appropriate time for equipment intervention without any reliability loss just by using a simple and cheap system which is not much used because professionals are not aware to its utility. Industrial facilities were evaluated by fail detection and historical analysis in some equipment in order to show feasibility of vibration analysis through a before-during-after process. The plant evaluated is part of a chemical multinational located in Guaratinguetá-SP. At this time, that plant had around 650 critical equipment monthly monitored and no unscheduled shutdown was registered in one year period due to equipment monitoring

Efeito da variação da velocidade de corte e de avanço no torneamento de Eucalipto

Due to the rapid development of some species such as pine and eucalyptus and a growing demand for raw materials, timber, there was a need for detailed studies to better use and higher quality in products derived from wood. In order to contribute to to better utilization of wood ,this study aims to analyze the quality of the wood surface after machining Corymbia citrodora around, with varying feed rates (40, 70, 100 mm/mim), shear rate (1.88, 2.19, 2.51 m/s) and with the use of inserts for turning new and used (cemented carbide). 18 were used bodies and each body was made three different assays for each test were a total of 54 tests three replicates. This study will also addres the analysis of power consumption for each of the tests. With the results obtained through experiments, including the surface roughness of parts and power consumption for each test, we try to evaluate the power consumption in machining with the variations in cutting speed and feed, with two tools carbide

Controle de velocidade e tração de rodas independentes para veículos elétricos

This work presents a proposal to replace thetraditional system of traction electric car that usesone electric motor and a mechanical differential, by two electric motors of lower power, controlled byelectronic control low cost. The proposed control isopen loop and uses the technique of Pulse WidthModulation (PWM), discrete and synchronizedaiming to reduce the generation of harmonics. The implementation of two smaller motor one on each wheel-drive distributes the weight of the vehicle, improving the heat exchange of the windings,beyond enable the power components supporting a current of 50% predicted for only one motor . The solution adopted for being open-loop, has a similar behavior to the mechanical differential, where theeffort imposed by the trajectory makes the velocity distribution between the wheels be appropriate tovehicle trajectory

Efeito da ativação física e química do gel clareador na velocidade de penetração do peróxido de hidrogênio: estudo in vitro

This study evaluated the effect of physical and chemical activation on the speed of penetration of hydrogen peroxide bleaching agents present in different concentrations through the enamel and dentin. One hundred and twenty bovine incisors were used, which were obtained enamel/dentin discs of the buccal surface, with 6 mm in diameter. The samples were divided into six groups: G1 - Hydrogen Peroxide Gel 20%, G2 - Hydrogen Peroxide Gel 20% with light activation, G3 - Hydrogen Peroxide Gel 20% with Manganese Gluconate; G4 - Hydrogen Peroxide Gel 35%; G5 - Hydrogen Peroxide Gel 35% with the light activation and G6 - Hydrogen Peroxide Gel 35% with Manganese Gluconate. The specimens were placed in a transparent support on which there was a substance sensitive to hydrogen peroxide immediately below and in contact with the specimen. After the procedures for applying the gel for each group, one video camera was positioned and operated to monitor the time of penetration of peroxide in each specimen. The recording ended after changing the color of the fluid revealed in all specimens and times were noted for comparison. ANOVA analysis showed that concentration and type of activation of bleaching gel significantly influenced the diffusion time of hydrogen peroxide (P 0.05). 35% hydrogen peroxide showed the lowest diffusion times compared to the groups with 20% hydrogen peroxide gel. The light activation of hydrogen peroxide decrease significantly the diffusion time compared to chemical activation. The highest diffusion time was obtained with 20% hydrogen peroxide chemically activated. The diffusion time of hydrogen peroxide was dependent on activation and concentration of hydrogen peroxide. The higher concentration of hydrogen peroxide diffused through dental tissues more quickly

Modulação da velocidade do andar em indivíduos com doença de Parkinson em estágio leve e moderado

A doença de Parkinson (DP) é uma patologia crônica, degenerativa e progressiva acarretada pela perda de neurônios dopaminérgicos da substância negra (parte compacta), localizada nos núcleos da base. Os comprometimentos na marcha estão entre as principais consequências da DP. Entretanto, pouco se conhece sobre o efeito do estágio da doença na modulação da velocidade do andar. Assim, o objetivo do estudo foi verificar como pacientes em diferentes estágios da DP modulam os parâmetros do andar quando requeridos a andar em máxima velocidade. Os participantes do estudo foram indivíduos com DP idiopática em estágio unilateral (entre 1 e 1,5 na Escala de Hoehn & Yahr) e bilateral (entre 2 e 3 na Escala de Hoehn & Yahr). Inicialmente, os participantes foram submetidos a uma avaliação clínica, realizada por um médico neuropsiquiatra, para verificar o acometimento geral e o estágio da doença. Os dados da avaliação clínica foram utilizados para a distribuição dos participantes entre os dois grupos. Em seguida, os participantes foram convidados a andar sobre uma passarela de 10m de comprimento em duas condições experimentais: Velocidade preferida e velocidade máxima. Somente o grupo bilateral não foi capaz de modular o comprimento da passada na condição de velocidade máxima. Os resultados sugerem que a evolução da DP compromete a capacidade dos pacientes em modular a amplitude de movimentos (comprimento da passada) quando são requeridos a andar em velocidade máxima

Velocidade de semeadura e profundidade da haste em sistema plantio direto de milho e soja

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Monitoramento da condição da ferramenta de dressagem usando sinais de vibração e modelos neurais

Pós-graduação em Engenharia Elétrica - FEB

Aplicação de adesivos estruturais em painéis de carros

The automobile industry is increasingly interested in reducing vehicle weight for greater speed, lower fuel consumption and emissions, through innovation of materials and processes. One way to do this is to seek the replacement of conventional processes by the use of structural adhesives. Structural adhesives are highly resistant materials, which can replace rivets, bolts and welds allowing the substrate / adhesive assemble is stronger than the substrate itself. One of the major advantages of gluing with respect to welding is its esthetic appearance, since it does not leave marks. For this reason, parts to be soldered require a minimum thickness so that the marks do not appear, since the pieces from gluing have no restriction as to the thickness. By replacing the vibration welding process for gluing process of the instrument panel parts of an automobile, one obtains a reduction of the thickness of the parts and therefore it decreases the weight of the car. This work aims to study the various structural adhesives that already exist on the market to be applied on the instrument panel. The mechanical test performed to measure the maximum adhesive strength was the Lap Shear Test at 23°C (room temperature), -35°C and 85°C. The types of adhesives used were the hot-melt and the bi-component. By the results obtained, it is in favor using the bi-component for application to the union of instrument panel parts

Estudo da velocidade de despassivação de aços em estruturas de concreto armado, em meio de cloreto

The aim of the present study was to investigate the corrosion resistance in chloride medium of two cylindrical steel samples from civil construction (CA-50 and CA-60). For this purpose, electrochemical measurements were performed in NaCl solution, 4.0 g/L, naturally aerated. According to electrochemical responses, it was observed an active dissolution process at open circuit potential for both steels. In this comparative study, the differences between CA-50 and CA60 were not significant, since the values of polarization resistance estimated by EIS were the same order of magnitude for both types of steel (oscillating between 200 and 500 Ohm). For all evaluated thicknesses of concrete reinforcement, these values ranged between 2 and 9 kOhm, and the lower value was associated with lower thickness, particularly at 7, 21 and 35 days. When these results were compared with those determined for the CA-60, it was found that the layer of concrete reinforcement provide a protection against corrosion in chloride medium at least ten times larger

Treinamento com vibração do corpo todo resulta em ganho de força muscular e mobilidade funcional em indivíduos com doença de Parkinson

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Dinâmica não linear e projeto de controle em sistemas de transporte vertical: comportamentos periódicos e caóticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Os efeitos da manipulação do sistema proprioceptivo na locomoção de pessoas com doença de Parkinson com e sem congelamento da marcha: desenvolvimento, otimização e aplicabilidade de um sistema de vibração muscular

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of railway track vibration induced by passing trains on an energy harvesting device

Pós-graduação em Engenharia Mecânica - FEIS

Vibração incidente sobre o corpo inteiro do operador de trator agrícola ensaiado em pista de vibração com diferentes lastros, velocidades e pressões de inflação dos pneus

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