Vibrations
Mostrando 37-48 de 372 artigos, teses e dissertações.
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37. Modificación de las propiedades estructurales, eléctricas y magnéticas del BiFeO3 por la incorporación de Ba y Nb
Bismuth ferrite (BFO) and Ba-Nb-substituted BFO with compositions Bi1-xBaxFeO3 (x= 0, 0.10, 0.15 y 0.20), BiFe1-yNbyO3 (y= 0, 0.03, 0.06 y 0.09) y Bi1-xBaxFe1-yNbyO3 (x= 0.10 (y= 0, 0.03, 0.06 y 0.09) powders were synthesized using the citrate-gel method. Infrared spectroscopy indicated shifting of Bi/Ba-O and Fe/Nb-O bond vibrations and a structural transit
Quím. Nova. Publicado em: 2017-02
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38. Effect of Sonic Vibrations on Bond Strength of Fiberglass Posts Bonded to Root Dentin
Resumo Vibrações sônicas podem melhorar a resistência e a durabilidade da união de pinos de fibra de vidro, melhorando a penetração do sistema adesivo à dentina, bem como o escoamento do cimento. O objetivo deste estudo foi avaliar o efeito da vibração sônica na resistência de união de pinos de fibra de vidro à dentina radicular, através de en
Braz. Dent. J.. Publicado em: 12/12/2016
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39. Axial Static Load Dependence Free Vibration Analysis of Helical Springs Based on the Theory of Spatially Curved Bars
Abstract This work addresses an accurate and detailed axial static load dependence linearly elastic free vibration analysis of cylindrical helical springs based on the theory of spatially curved bars and the transfer matrix method. For a continuous system, governing equations comprise coupled vibration modes namely transverse vibrations in two orthogonal pla
Lat. Am. j. solids struct.. Publicado em: 2016-12
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40. Three-Dimensional Rail-Bridge Coupling Element of Unequal Lengths for Analyzing Train-Track-Bridge Interaction System
Abstract A three-dimensional rail-bridge coupling element of unequal lengths in which the length of the rail element is shorter than that of the bridge element is presented in this paper to investigate the spatial dynamic responses of a train-track-bridge interaction system. Formulation of stiffness and damping matrices for the fastener, ballast, and bearing
Lat. Am. j. solids struct.. Publicado em: 2016-12
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41. Design and Damping Analysis of a New Eddy Current Damper for Aerospace Applications
Abstract In order to reduce the structural vibrations of a mechanical system used in aerospace, a new sketch of eddy current damper (ECD), consisting of one cylindrical permanent magnet, two ring-shape copper plates, one axial transmission shaft and electromagnetic shield, is proposed. Three dimensional (3D) electromagnetic transient analysis on damping perf
Lat. Am. j. solids struct.. Publicado em: 2016-11
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42. MODIFICAÇÃO DE MEMBRANA DE POLIAMIDA VIA SOL-GEL E INCORPORAÇÃO DE COMPOSTO DE EURÓPIO (III) LUMINESCENTE
Over the last decades, the combination of different technologies to search for systems with new properties and features has brought various segments of biological and earth sciences together. Additive manufacturing, known as rapid prototyping, combined with the sol-gel methodology enables the production of novel systems with applications in many scientific f
Quím. Nova. Publicado em: 2016-11
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43. Nonlinear Vibrations of Cantilever Timoshenko Beams: A Homotopy Analysis
Abstract This study analyzes the fourth-order nonlinear free vibration of a Timoshenko beam. We discretize the governing differential equation by Galerkin's procedure and then apply the homotopy analysis method (HAM) to the obtained ordinary differential equation of the generalized coordinate. We derive novel analytical solutions for the nonlinear natural fr
Lat. Am. j. solids struct.. Publicado em: 2016-10
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44. Tip Deflection Determination of a Barrel for the Effect of an Accelerating Projectile Before Firing Using Finite Element and Artificial Neural Network Combined Algorithm
Abstract For realistic applications, design and control engineers have limited modelling options in dealing with some vibration problems that hold many nonlinearity such as non-uniform geometry, variable velocity loadings, indefinite damping cases, etc. For these reasons numerous time consuming experimental studies at high costs must be done for determining
Lat. Am. j. solids struct.. Publicado em: 2016-10
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45. Structural, Thermal and Optical Properties of Pure and Mn2+ Doped Poly(Vinyl Chloride) Films
Pure and Mn2+ doped poly(vinyl chloride) (PVC) polymer films were prepared using the solution cast technique. The prepared samples have been characterized by X-ray diffraction (XRD), UV-Vis Spectroscopy (UV-Vis), Fourier transform infrared (FTIR) Spectroscopy, Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Electron Paramagnetic Re
Mat. Res.. Publicado em: 19/09/2016
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46. Study of Vibrations in a Short-Span Bridge Under Resonance Conditions Considering Train-Track Interaction
Abstract Resonance is a phenomenon of utmost importance in railways engineering, leading to vast damages both in track and vehicles. A short-span bridge has been modeled by means of a finite elements method model, calibrated and validated with real data, to study resonance vibrations induced by the passage of trains. Furthermore, the influence of vehicle spe
Lat. Am. j. solids struct.. Publicado em: 2016-07
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47. Simplified Analytical Approach to Evaluate the Nonlinear Dynamics of Elastic Cylindrical Shells Under Lateral Blast Loads
Abstract This paper presents an analytical solution to predict the nonlinear forced vibrations of elastic thin-walled cylindrical shells under suddenly applied loads. Interest in this problem is motivated by effects due to explosions on fluid-storage metal tanks. The model is based on the energy criterion due to Lagrange, in which the kinematic nonlinear rel
Lat. Am. j. solids struct.. Publicado em: 2016-07
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48. Nonlinear Dynamic Analysis of Telescopic Mechanism for Truss Structure Bridge Inspection Vehicle Under Pedestrian Excitation
Abstract Nonlinear dynamic analysis of an axially moving telescopic mechanism for truss structure bridge inspection vehicle under pedestrian excitation is carried out. A biomechanically inspired inverted-pendulum model is utilized to simplify the pedestrian. The nonlinear equations of motion for the beam-pedestrian system are derived using the Hamilton's pri
Lat. Am. j. solids struct.. Publicado em: 2016-06