Banca de DEFESA: Roger Otávio Pires Montes

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Roger Otávio Pires Montes
DATE: 30/04/2024
TIME: 08:00
LOCAL: Plataforma Teams
TITLE:

Analytical-Numerical Study For Nonlinear Dynamic Analysis Coupled Cylindrical Shells-Fluid

KEY WORDS:

Cylindrical shells. Fluid-structure interaction. Free vibrations. Finite Element Method. Nonlinear analysis.

PAGES: 130
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Estruturas
SPECIALTY: Mecânica das Estruturas
SUMMARY:

Fluid-filled cylindrical shells are structures widely used in different engineering facilities such as oil rigs, nuclear power plants and storage tanks. In offshore structures, the action of ocean waves must be carefully evaluated, as the influence of fluid external to the outer walls of this structure can modify its dynamic behavior. This work presents an analytical-numerical approach to analyze the nonlinear vibrations of a cylindrical shell clamped, considering the presence of external and internal fluid with the inclusion of the effects of the movement of the free surface of the internal fluid. The strain fields and curvature changes of the mean surface of the cylindrical shell are described by the nonlinear Sanders-Koiter theory. The modal expansions, which describe the displacement fields of the clamped-free cylindrical shell, are obtained from the Chebyshev polynomials. The action of ocean waves is developed from Airy's wave theory and diffraction theory, where a parametric analysis is made to evaluate the influence of this charge on the dynamic behavior of cylindrical shells. Finally, the Rayleigh-Ritz method together with Hamilton's principle are used to discretize the nonlinear equations of motion of the system which, in turn, are linearized and solved to obtain the natural frequencies and vibration modes of the cylindrical shell with fluid-structure interaction. The results obtained are compared, when possible, with other studies found in the literature. In addition, a numerical analysis using the Finite Element Method using ANSYS commercial software is developed to evaluate the reliability and convergence of the analytical-numerical results obtained. The consideration of the external and internal fluid for analysis of free vibrations with application of hydrodynamic pressures is important, as it incorporates additional mass and reduces the values of natural frequencies. The influence of the free surface also alters the free vibrations of the cylindrical shell and, for large structures, a considerable effect is observed that cannot be disregarded. A nonlinear analysis of the dynamic behavior of the problem is also made, by obtaining the responses in time and phase plans, evaluating the dynamic nonlinear behavior of the cylindrical shells.

COMMITTEE MEMBERS:
Presidente - 404485 - LINEU JOSE PEDROSO
Interno - 1998608 - ARTUR ANTONIO DE ALMEIDA PORTELA
Externo à Instituição - Davidson de Oliveira França Júnior - UNIFAL-MG
Externo à Instituição - FREDERICO MARTINS ALVES DA SILVA - UFG
Externo à Instituição - ROBERTO DALLEDONE MACHADO - UFPR
Externo à Instituição - ZENÓN JOSÉ GUZMÁN NÚÑEZ DEL PRADO - UFG