Bifurcation Theory
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Determination of Forming Limit Diagrams Based on Ductile Damage Models and Necking Criteria
Abstract In this paper, forming limit diagrams (FLDs) for an aluminum alloy are predicted through numerical simulations using various localized necking criteria. A comparative study is conducted for the FLDs determined by using the Lemaitre damage approach and those obtained with the modified Gurson-Tvergaard-Needleman (GTN) damage model. To this end, both d
Lat. Am. j. solids struct.. Publicado em: 2017-10
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2. Influence of the Yield Surface Curvature on the Forming Limit Diagrams Predicted by Crystal Plasticity Theory
Abstract The aim of this paper is to investigate the impact of the microscopic yield surface (i.e., at the single crystal scale) on the forming limit diagrams (FLDs) of face centred cubic (FCC) materials. To predict these FLDs, the bifurcation approach is used within the framework of rate-independent crystal plasticity theory. For this purpose, two micromech
Lat. Am. j. solids struct.. Publicado em: 2016-12
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3. Gap Dependent Bifurcation Behavior of a Nano-Beam Subjected to a Nonlinear Electrostatic Pressure
This paper presents a study on the gap dependent bifurcation behavior of an electro statically-actuated nano-beam. The sizedependent behavior of the beam was taken into account by applying the couple stress theory. Two small and large gap distance regimes have been considered in which the intermolecular vdW and Casimir forces are dominant, respectively. It h
Lat. Am. j. solids struct.. Publicado em: 2014
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4. Thermomechanical buckling oftemperature-dependent FGM beams
Buckling of beams made of functionally graded materials (FGM) under thermomechanical loading is analyzed herein. Properties of the constituents are considered to be functions of temperature and thickness coordinate. The derivation of the equations is based on the Timoshenko beam theory, where the effect of shear is included. It is assumed that the mechanical
Lat. Am. j. solids struct.. Publicado em: 2013-03
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5. Controle de caos e saltos entre atratores em um sistema com impactos / Control of caos and basin hopping in a system with impacts
For a mechanical system, described by the impact-pair model, we studied the control of chaos by a parametric perturbation and the basin-hopping phenomeno. For this nonintegrable system, we obtained numerically the evolution of its dynamical variables for a large set of initial conditions and control parameters. For this analysis, we used phase planes, Poinca
Publicado em: 2010
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6. Entanglement, bifurcation and chaos in the Jahn-Teller E x beta / Emaranhamento, bifurcação e caos no modelo de Jahn-Teller E x beta
In this work we realize a study of entanglement for the Jahn-Teller E Ä b model, wich describes the interaction of a qubit with an oscillator mode, and relate it with the bifurcation of the fixed point of the classical analogue of the model. We also study qualitatively the ocurrence of chaos and its variation as a function of the parameters of the system. W
Publicado em: 2009
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7. Bifurcações de campos vetoriais descontínuos / Bifurcations of discontinuous vector fields
Let M be a connected and compact set of the plane which is the union of the connected subsets N and S. Let Z_L=(X_L,Y_L) be a one-parameter family of discontinuous vector fields, where X_L is defined on N and Y_L on S. The two fields X_L, Y_L and their dependences on L are smooths, i. e., are of C^\infty class; the discontinuity happens in the common boundar
Publicado em: 2009
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8. The Conley index for discontinuous vector fields / O indice de Conley para campos de vetores descontinuos
The Conley index is a used as a topological invariant in the analysis of the qualitative behavior of dynamical systems. lnitially the theory was developed for continuous flows in finite dimensional spaces and later extended to the infinite dimensional setting as well as to the discrete case. ln this work, we present a Conley index theory for a class of disco
Publicado em: 2008
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9. Bifurcações em PLLs de terceira ordem em redes OWMS. / Bifurcations on 3rd order PLLs in OWMS networks.
Este trabalho apresenta um estudo qualitativo das equações diferenciais nãolineares que descrevem o sincronismo de fase nos PLLs de 3ª ordem que compõem redes OWMS de topologia mista, Estrela Simples e Cadeia Simples. O objetivo é determinar, através da Teoria de Bifurcações, os valores ou relações entre os parâmetros constitutivos da rede que pe
Publicado em: 2008
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10. Bifurcação de Hopf generalizada para um sistema planar suave por partes
In this work we use the qualitative theory of the di?erential equations to quickly study the Hopf bifurcation for a smooth planar dynamical system under the variation of the control parameter of the system, and a generalized Hopf bifurcation emanated from a corner for piecewise smooth planar dynamical system, about the generation of a branch of periodic orbi
Publicado em: 2007
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11. Weak three dimensionality of a flow around a slender cylinder: the Ginzburg-Landau equation
In this paper a weak three-dimensionality of the flow around a slender cylinder is considered and the related model, the so-called Ginzburg-Landau equation, is here obtained as an asymptotic solution of the 3D (discrete) Navier-Stokes equation. The derivation is in line with existing slender bodies theories, as the Lifting Line Theory, for example, where the
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-12
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12. A study about maximum loading in electrical power systems. / Estudo de máximo carregamento em sistemas de energia elétrica.
Este trabalho apresenta um estudo sobre o método da continuação aplicado ao problema de fluxo de potência. Definições e conceitos de estabilidade de tensão são descritos de forma a explicitar as diferenças e semelhanças existentes com relação ao estudo de máximo carregamento em sistemas de energia elétrica. Uma síntese da teoria da bifurcaçã
Publicado em: 2003