Variational Methods
Mostrando 1-12 de 53 artigos, teses e dissertações.
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1. Approximate solutions of large amplitude vibration of a string
Abstract In the present study, the response of a flexible string with large amplitude transverse vibration is studied utilizing amplitude-frequency formulation, improved amplitude-frequency formulation and max-min approach. In order to verify the accuracy of these approaches, obtained results are compared with other methods such as variational approach meth
Lat. Am. j. solids struct.. Publicado em: 04/06/2018
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2. Analysis of Geometrically Nonlinear Vibrations of Functionally Graded Shallow Shells of a Complex Shape
Abstract Geometrically nonlinear vibrations of functionally graded shallow shells of complex planform are studied. The paper deals with a power-law distribution of the volume fraction of ceramics and metal through the thickness. The analysis is performed with the use of the R-functions theory and variational Ritz method. Moreover, the Bubnov-Galerkin and the
Lat. Am. j. solids struct.. Publicado em: 2017-09
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3. Explicit solution of the large amplitude transverse vibrations of a flexible string under constant tension
This paper presents the analytical simulation of string with large amplitudes using the Variational Iteration Method (VIM) and Hamiltonian Approach (HA). In order to verify the precision of the presented methods, current results were compared with He's Variational Approach and Runge-Kutta 4th order. It has been found that these methods are well suited for a
Lat. Am. j. solids struct.. Publicado em: 2014-05
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4. Dynamic model of large amplitude vibration of a uniform cantilever beam carrying an intermediate lumped mass and rotary inertia
In this paper, a mathematical model of large amplitude vibration of a uniform cantilever beam arising in the structural engineering is proposed. Two efficient and easy mathematical techniques called variational iteration method and He's variational approach are used to solve the governing differential equation of motion. To assess the accuracy of solutions,
Lat. Am. j. solids struct.. Publicado em: 2014-03
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5. Study of nonlinear vibration of Euler-Bernoulli beams by using analytical approximate techniques
In this paper, nonlinear responses of a clamped-clamped buckled beam are investigated. Two efficient and easy mathematical techniques called He's Variational Approach and Laplace Iteration Method are used to solve the governing differential equation of motion. To assess the accuracy of solutions, we compare the results with the Runge-Kutta 4th order. The res
Lat. Am. j. solids struct.. Publicado em: 2014-01
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6. Dynamical stability and parametrical vibrations of the laminated plates with complex shape
The problem of nonlinear vibrations and stability analysis for the symmetric laminated plates with complex shape, loaded by static or periodic load in-plane is considered. In general case research of stability and parametric vibrations is connected with many mathematical difficulties. For this reason we propose approach based on application of R-functions th
Lat. Am. j. solids struct.. Publicado em: 2013-01
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7. Estudo de uma classe de equações elípticas via métodos variacionais e topológicos / Study of a class of elliptic equations via variational and topological methods
Alguns problemas elípticos assintoticamente lineares são considerados e é provada a existência de solução. Os principais resultados são estabelecidos de dois modos distintos e as provas são baseadas em resultados clássicos da teoria de pontos críticos, a saber: minimização, princípio variacional de Ekeland, grau topológico, teorema do ponto de
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/04/2012
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8. Problemas Elípticos Assintoticamente Lineares / An Asymptotically Linear Elliptic Problem
Nesta dissertação analisamos questões de existência e multiplicidade de soluções do problema de Dirichlet elíptico assintoticamente linear. Para obtermos os nossos principais resultados utilizamos métodos variacionais, tais como o Teorema do Passo da Montanha um Teorema de Linking. Além disso, utilizamos a redução de Liapunov-Schmidt.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/02/2012
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9. Problemas Elípticos Assintoticamente Lineares / An Asymptotically Linear Elliptic Problem
Nesta dissertação analisamos questões de existência e multiplicidade de soluções do problema de Dirichlet elíptico assintoticamente linear. Para obtermos os nossos principais resultados utilizamos métodos variacionais, tais como o Teorema do Passo da Montanha um Teorema de Linking. Além disso, utilizamos a redução de Liapunov-Schmidt.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/02/2012
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10. Stability analysis of carbon nanotubes based on a novel beam model and its comparison with Sanders shell model and molecular dynamics simulations
We study the effects of small-scale parameter on the buckling loads and strains of nanobeams, based on nonlocal Timoshenko beam model. However, the lack of higherorder boundary conditions leads to inconsistencies in critical buckling loads. In this paper, we apply a novel approach based on nonlocal Timoshenko kinematics, strain gradient approach and variatio
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2012-06
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11. Recent developments of some asymptotic methods and their applications for nonlinear vibration equations in engineering problems: a review
This review features a survey of some recent developments in asymptotic techniques and new developments, which are valid not only for weakly nonlinear equations, but also for strongly ones. Further, the achieved approximate analytical solutions are valid for the whole solution domain. The limitations of traditional perturbation methods are illustrated, vario
Lat. Am. j. solids struct.. Publicado em: 2012-04
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12. Segmentação de imagens via competição entre regiões fuzzy: abordagens paramétricas e não-paramétricas
A segmentação de imagens é uma importante etapa existente nos sistemas de reconhecimento de padrões e extração de características. Seu objetivo é subdividir uma imagem em suas regiões constituintes. Dentre os diversos trabalhos publicados na literatura, destacam-se os métodos baseados em princípios variacionais, que são ferramentas eficazes para
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/08/2011