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Showing 1 to 20 of 44 for “"Vibrações"”.
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Vibrações de estruturas aporticadas espaciais estaiadas
A numerical tool for geometric nonlinear static and linear dynamic analysis of stayed spatial frame structures is presented. The numerical procedures and modelling technics are developed towards near future analysis of long span stayed bridges. The developed approach mapes use of well established …
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Vibrações de cascas cilíndricas delgadas contendo fluido
The main theoretical and experimental results for the dynamic interaction occuring between fluid and thin cylindrical shells, which result from a strong coupling among the vibration modes, are presented herein. Emphasis is given to the used experimental techniques and obtained test results which …
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Verificação experimental de vibrações paramétricas em vigas
Experimental investigation of parametric resonance of a bar subjected to an axial compressive force P, smaller than the buckling load and to an oscillating torque of the type T = T₀ + T₁1 cos Ω t, , where T₀, T₁ e Ω are independent pameters. The regions of elastodynamic instability are determined …
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Vibrações e estabilidade paramétrica de cascas axissimétricas
The general problem of Dynamics of Elastic Bodies is presented, and the problems of dynamic response and stability of rotating axisyrnmetric shells, under a non-rotating load, are studied. Using a Fourier series expansion for the circunferential variable it is shown that this load generates a …
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Estudo experimental de um excitador de vibrações
This work developed a prototype with which it's possible to study an excitator of vibrations. As structure of the model, two basic patts (loudspeaker and mechanical addition) were got which together allow us to establish the main characteristics in what concerns to the referred excitator. Built and …
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Controle inteligente de vibrações utilizando amortecedor magneto reológico
Magnetorheological (MR) dampers are widely used in industrial applications such as vibration control of machine tools and structures subject to seismic earthquakes; active or semi-active suspensions in the automotive industry, as well as clutch and brake systems; and in the biomechanics area with …
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Vibrações livres e forçadas no modelo de Timoshenko
… viga descrita pela equação de Timoshenko e das vibrações forçadas, devidas a influência de cargas externas. Os modos vibratórios foram obtidos com o uso da base dinâmica, gerada por uma resposta livre e suas derivadas. Esta resposta é caracterizada por condições iniciais impulsivas. Simulações …
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Vibrações livres de viga de seção transversal variável
This work deals with the problem of the determination of the natural frequencies of transverse vibrations of beams of variable cross section, in particular beams with section heigh varying according to a polynbmial law. Ritz method is used for the determinátion of the natural frequencies, dueto its …
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Vibrações de placas sandwich enrijecidas por barras conectoras
Analysis of the free transverse vibration equations of retangular sandwich-type plates including spaced transverse posts between the faces which introduce additional stiffness in the core, under compressive uniforme load acting in the midplane, as well as the determination of the critical loads by …
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Processamento digital de sinal: aplicações em acústica e vibrações
A partir du travail de Goff, ainsi que des études sur la transformée de Fourier rapide, et sur le cepstrum ont été élaborés plusieurs estimateurs de fonctions de correlation, spectre, cepstrum. Les elements d'une chaine d'aquisition de données ont été assemblés dans le but d'utiliser des programmes …
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Neutralizador dinâmico de vibrações torcionais viscoelásticos aplicado em sistemas rotodinâmicos
Dynamic viscoelastic vibration neutralizers are devices used in the passive control of vibrations. The main characteristics that make them an advantageous choice are directly related to the viscoelastic materials used in the construction of these auxiliary systems. This doctoral thesis deals with …
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Equilíbrio e vibrações induzidas por vórtices de "risers" de perfuração
Presents a study about drilling risers used by semisubmersible platforms in order to drill wells in deep waters. Firstly, a study about static equilibrium is presented. This allows to select adequate risers for places with usual natural conditions. The selection takes into account the riser …
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Vibrações transversais de viga comprimida apoiada sobre sistema massa-mola
The principal problem undertaken is this work is the determination of the natural frequencies of lateral vibrations of a beam with axial load, wich carries a concentrated mass and spring located at any point along the length of the beam. The case of a beam with two concentrated masses and springs …
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Vibrações induzidas por vórtices em estruturas tipo Jumpers em águas profundas
The research for new oil reserves has led the offshore industry to seek ways to adapt to the new types of environment: deep and ultra-deep waters. The demand for pipelines (rigid and / or flexible) meant that oil and gas companies not only invested in the production of equipment, but also in …
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Uma formulação de elementos de contorno para análise de vibrações livres
This work presents an alternative formulation for the boundary element analysis of free vibrations of elastic bodies in plane stress or plane strain. The main characteristic of this method is the transformation of the inertial domain integral into equivalent boundary integrals, by employing special …
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Caracterização dos níveis de vibração em motoristas de ônibus : um enfoque no conforto e na saúde
… consiste em um estudo para avaliar os níveis de vibrações do corpo humano, do segmento mão-braço, e a transmissibilidade a que estão sujeitos os motoristas de ônibus urbanos. As medições foram realizadas, no eixo vertical, de acordo com as recomendações das normas ISO 2631 (1974 e 1997) e ISO …
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Identificação de falhas em engrenagens na transmissão de trator agrícola por meio de análise de vibrações
… de análise de falhas, por meio de análise de vibrações, para a bancada de final de linha das transmissões dos tratores linha 5000 da John Deere Brasil, o qual tem como finalidade diferenciar transmissões aprovadas de transmissões com defeito em engrenagens na caixa de marchas, e também …
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