Nonlinear Modal Analysis
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Nonlinear Vibration and Mode Shapes of FG Cylindrical Shells
Abstract The nonlinear vibration and normal mode shapes of FG cylindrical shells are investigated using an efficient analytical method. The equations of motion of the shell are based on the Donnell’s non-linear shallow-shell, and the material is assumed to be gradually changed across the thickness according to the simple power law. The solution is provided
Lat. Am. j. solids struct.. Publicado em: 2017-03
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2. Extração e avaliação da dinâmica não-linear da voz utilizando vídeo de alta velocidade da laringe / Extraction and evaluation of vocal folds dynamics using high-speed laryngeal imaging
No contexto da fonação, as pregas vocais são responsáveis pela produção primária do sinal de voz na laringe. Tão importantes quanto complexas, elas exibem uma dinâmica rica e uma série de comportamentos que determinam as características fundamentais do sinal emitido pela boca. Com o intuito de avaliar suas propriedades sob a luz dos métodos da di
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/04/2012
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3. Optimization of laminated composite plates and shells using genetic algorithms, neural networks and finite elements
Structural optimization using computational tools has become a major research field in recent years. Methods commonly used in structural analysis and optimization may demand considerable computational cost, depending on the problem complexity. Therefore, many techniques have been evaluated in order to diminish such impact. Among these various techniques, Art
Latin American Journal of Solids and Structures. Publicado em: 2011
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4. Nonlinear turbulent transonic flow phenomena influence on aeroelastic stability analysis.
The present work is aimed at studying the influence of viscous effects in transonic aeroelastic analyses. To achieve this goal, a two-dimensional and viscous aeroelastic computational solver, for CAE analysis, is developed, which uses unstructured computational meshes and which is able to capture the main aeroelastic phenomena relevant in the transonic regim
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/12/2010
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5. Nonlinear turbulent transonic flow phenomena influence on aeroelastic stability analysis.
The present work is aimed at studying the influence of viscous effects in transonic aeroelastic analyses. To achieve this goal, a two-dimensional and viscous aeroelastic computational solver, for CAE analysis, is developed, which uses unstructured computational meshes and which is able to capture the main aeroelastic phenomena relevant in the transonic regim
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/12/2010
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6. NONLINEAR DYNAMICS, INSTABILITY AND CONTROL OF STRUCTURAL SYSTEMS WITH MODAL INTERACTION / DINÂMICA NÃO-LINEAR, INSTABILIDADE E CONTROLE DE SISTEMAS ESTRUTURAIS COM INTERAÇÃO MODAL
The aim of this thesis is to study the influence of coupled buckling modes on the static and particularly on the nonlinear dynamic behavior of structural components liable to buckling. For this, two discrete two degrees of freedom models known for their complex nonlinear behavior are selected: the well-known Augusti¿s model and a simplified model of cable-s
Publicado em: 2010
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7. Identification of material properties using full-field and non contact measurements
In the present work, the Digital Image Correlation (DIC) measurement method is used to obtain the displacement field of specific regions of a cantilever beam under bending. These fields are used within an inverse analysis scheme in order to obtain the elasticity modulus of the beam material. The parameter estimation is performed by means of the minimization
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2009-09
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8. 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
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9. EFFICIENCY ASSESSMENT OF ADVANCED MODAL ANALYSIS AS COMPARED TO TECHNIQUES BASED ON NUMERICAL INVERSE TRANSFORMS / COMPARAÇÃO DO DESEMPENHO COMPUTACIONAL DA TÉCNICA DE SUPERPOSIÇÃO MODAL AVANÇADA COM TÉCNICAS DA TRANSFORMADA DE LAPLACE
An established technique to solve time-dependent problems is the formulation of a complete frequency-domain analysis via Laplace or Fourier transforms, with subsequent ad hoc expression of results by numerical inversion. Although usually easy to implement, such a transform inversion is computationally intensive, if accurate results are desired, and liable to
Publicado em: 2008
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10. MODELOS DE DIMENSÃO REDUZIDA PARA ANÁLISE DAS OSCILAÇÕES NÃO-LINEARES E ESTABILIDADE DE CASCAS CILÍNDRICAS / LOW DIMENSIONAL MODELS FOR NONLINEAR VIBRATION ANALYSIS AND STABILITY OF CYLINDRICAL SHELLS.
The nonlinear vibrations and stability of a fluid-filled cylindrical shell is investigated using reduced order models. First, the nonlinear equations of motion of the cylindrical shell are deduced based on the expressions for the potential and kinetic energy, which are obtained using Donnell shallow shell theory. The internal fluid is considered to be irrota
Publicado em: 2008
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11. MÉTODOS APROXIMADOS DE SOLUÇÃO DE SISTEMAS DINÂMICOS NÃO-LINEARES / APPROXIMATE SOLUTION METHODS FOR NONLINEAR DYNAMICAL SYSTEMS
Nonlinear dynamical systems are rather common in engineering. This class of problems is usually solved by numerical integration or through the use of ap- proximate analytical methods (perturbation methods) or semi-analytical meth- ods such as the harmonic balance method. The numerical integration is a slow and cumbersome process in parametric analyses. The o
Publicado em: 2008
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12. Structural behavior of tower stell to support a wind turbine / Comportamento estrutural de torres de aço para suporte de turbinas eólicas
The increasing demand for electricity required by individual and industrial consumers brings back the issues related to the exhaustion of the exiting fossil energy sources and leads to the evident needs for investments in research topics that focus on improving, developing available renew able energy sources or even creating some novel energy renewable alter
Publicado em: 2008