Mechanical Vibrations
Mostrando 13-24 de 55 artigos, teses e dissertações.
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13. Efeito da aplicação de vibração mecânica localizada durante o treinamento de força sobre a hipertrofia muscular
Several studies indicate that the addition of vibrations to the strength training (ST) may contribute to the development of muscle strength and athletic performance. The aim of this study was to verify the chronic effect of application of mechanical vibration during ST on muscle hypertrophy. The sample consisted of 20 male volunteers, mean age 21,3 ± 3,02 y
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/04/2012
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14. Posicionamento de sensores/atuadores e escolha de funções de ponderação no controle H-infinito de vibrações / Placement of sensors/actuators and selection of weighting functions in H-infinity control of vibrations
In this work it was used the H infinite control to atenuate vibrations in mechanical structures. Linear matrix inequalities are used to find the optimal controller. Sensors and actuators are incorporated into the project. To determine the best place to allocate them in the structure two methods are used: the first is based on the highest closed-loop H infini
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/02/2012
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15. Análise do comportamento eletroaeroelástico de uma seção típica para geração piezelétrica de energia / Electroaeroelastic behavior analysis of a typical section for piezoelectric energy harvesting
Converting aeroelastic vibrations into electricity for low power generation has received growing attention over the past few years. In addition to potential applications for aerospace structures, the goal is to develop alternative and scalable configurations for wind energy harvesting to use in wireless electronic systems. The use of a typical airfoil sectio
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/02/2012
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16. Effect of parametric uncertainties on the performance of a piezoelectric energy harvesting device
The use of piezoelectric materials for the development of electromechanical devices for the harvesting or scavenging of ambient vibrations has been extensively studied over the last decade. The energy conversion from mechanical (vibratory) to electrical energy is provided by the electromechanical coupling between mechanical strains/stresses and electric char
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012
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17. Análise de fatores ergonômicos na colheita florestal mecanizada com ênfase na exposição humana às vibrações mecânicas / Analysis of ergonomic s factors at forest harvesting mechanized with emphasis on human exposure to mechanical vibrations
A colheita florestal mecanizada tem sido objeto de estudos ergonômicos no Brasil e no exterior, onde as pesquisas focam na avaliação de aspectos dimensionais e de usabilidade das máquinas de colheita disponíveis no mercado, visando a melhoria dos projetos e da segurança e saúde dos operadores. Entretanto, ainda são poucas as pesquisas direcionadas ao
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/11/2011
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18. Algoritmo de autoidentificação para o controle autônomo de vibrações em sistemas rotativos / Self-identification algorithm for the autonomous control of vibrations in rotating systems
Vibrações são intrínsecas às máquinas rotativas e, embora não possam ser completamente eliminadas, devem ser controladas de modo a se evitar fadiga e até mesmo falha da máquina. Neste contexto, devido à sua capacidade de alterar as características dinâmicas destas máquinas, os mancais ativos são uma solução efetiva a fim de se reduzir vibraç
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/07/2011
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19. Structural vibration control using extension and shear active-passive piezoelectric networks including sensitivity to electrical uncertainties
Active-Passive Piezoelectric Networks (APPN) integrate active voltage sources with passive resistance-inductance shunt circuits to a piezoelectric patch. This technique allows to simultaneously passively dissipate vibratory energy through the shunt circuit and actively control the structural vibrations. This work presents an analysis of active-passive dampin
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011-09
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20. Behavior of granite-epoxy composite beams subjected to mechanical vibrations
The capacity to damp mechanical vibrations is one of the most important properties of granite-epoxy composites, even superior to the cast iron one. For this reason, these materials have been adopted for manufacturing of tool machine foundations and precision instruments. This work presents a study concerning the behavior of particulate composite beams, based
Materials Research. Publicado em: 2010-12
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21. Modelo em elementos finitos para simulação de geradores piezelétricos de energia / Finite element modeling of a piezoelectric energy harvester
A conversão de energia de vibração disponível no ambiente em energia elétrica tem sido investigada por diversos pesquisadores nos últimos anos. O objetivo é alimentar sistemas de baixo consumo convertendo energia mecânica disponível no ambiente em energia elétrica. A literatura recente mostra que a transdução piezelétrica tem recebido a maior at
Publicado em: 2010
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22. Efects of vibration on quality of pot lities / Efeito da vibração na qualidade de lirios orientais em vaso
In Brazil losses of agricultural products during production and commercialization can reach up to 30% due to mechanical damages during harvest, transportation and storage, resulting in non-commercial quality products. The inadequate conditions of transport are related to lack of awareness of most chain segments, roads in bad conditions, drivers proper traini
Publicado em: 2009
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23. Performance evaluation of carbide tools on automotive valve guides reaming / Avaliação do desempenho de ferramentas de metal duro no alargamento de guias de válvulas automotivas
Reaming is a machining process with relatively low cost and suitable when high quality holes are required. The purpose of this work is to evaluate the quality of the holes made in automotive valve guides, fabricated with sintered steel. This study was based on parameters of surface roughness, roundness and cylindricity deviations, obtained with uncoated carb
Publicado em: 2009
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24. Mode localization of modular prestressed plate panels. / Localização de modos de vibração em painéis modulados de lajes protendidas.
In this research, the phenomenon of vibration modes localization in nearly periodic modular structures of linear and nonlinear behavior is studied. Of special interest is an application in Civil Engineering, lightly coupled periodic plate panels with small imperfections, mainly submitted to the variation of membrane forces introduced by prestress forces, whi
Publicado em: 2009