Mestrado em Engenharia Civil (EEC)
URI Permanente para esta coleção
Navegar
Navegando Mestrado em Engenharia Civil (EEC) por Assunto "Acoplamento modal"
Agora exibindo 1 - 1 de 1
Resultados por página
Opções de Ordenação
Item Uma introdução à influência da interação modal nas oscilações não lineares de cascas cilíndricas(Universidade Federal de Goiás, 2013-02-14) Rodrigues, Lara; Silva, Frederico Martins Alves da; http://lattes.cnpq.br/9929132527197884; Silva, Frederico Martins Alves da; Almeida, Sylvia Regina Mesquita de; Prado, Zenón José Guzmán Núñez Del; Gonçalves, Paulo BatistaThe aim of this work is to investigate the interaction and modal coupling phenomena on the nonlinear vibrations of simply supported cylindrical shell subject to both harmonic axial and lateral loads. The equations of motion of the cylindrical shell are deduced from their energy functionals and the strain field is based on the nonlinear Donnell shallow shell theory. Finally, the problem is reduced to a system of nonlinear ordinary differential equations by the application of the standard Galerkin method. The modal expansion that describes the transverse displacement of the shell is obtained by applying perturbation techniques, which identifies the importance of each term in the modal expansion by the power of the perturbation parameter. The Karhunen-Loève method is applied in order to verify the importance of each term in the modal expansion, quantifying the contribution of each of these terms in the total energy of the system. The starting solution used in the perturbation procedure contains two modes of vibration with the same natural frequency and their respective companion modes, yielding a modal expansion able to describe the modal interaction between these two modes. Then, the influence of modal interaction on the nonlinear behavior of the cylindrical shell, subjected to both lateral and axial harmonic load is studied. From the analysis of the resonance curves, the parametric instability and escape boundaries, the bifurcation diagrams, the basins of attraction and phase portraits of the cylindrical shell is possible to identify situations in which the consideration of modal interaction is necessary.