Vibrações não lineares de colunas esbeltas parcialmente enterradas
Nenhuma Miniatura disponível
Data
2019-03-22
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
In this work the nonlinear vibrations of partially embedded slender columns subjected to axial and
lateral loads are studied. The thin column is modelled by the nonlinear Euler-Bernoulli theory e the
soil behavior is described by two models: the Winkler model, which considers the load
proportional to the column deflection, and the Pasternack model, which takes into account two
different stiffness parameters to describe the elastic base. The equations of motion of the column
are derived from the energy functionals through the application of the Rayleigh-Ritz method along
with the Hamilton principle and, afterwards, are solved by the convenient method for each
analysis. It is accomplished a convergence study for the natural frequencies of the column in order
to assess qualitatively the response from each elastic base model. The post-critical and amplitude-
frequency relationship curves are obtained, allowing to understand how the system stiffness varies
with the increase of axial load and frequency amplitude, respectively. From the solution of the
equations of motion by the forth order Runge-Kutta method, the resonance curves, the parametric
instability and escape boundaries, the bifurcation diagrams and associated phase portraits are
obtained, enabling identifying in what ways the elastic base parameters from each model affect the
nonlinear vibrations of the column partially embedded. Lastly, it is presented a brief study about
the dynamic amplification in the column response when the lateral load is applied as an impact.
Descrição
Palavras-chave
Citação
PIRES FILHO, L. P. Vibrações não lineares de colunas esbeltas parcialmente enterradas. 2019. 98 f. Dissertação (Mestrado em Geotecnia, Estruturas e Construção Civil) - Universidade Federal de Goiás, Goiânia, 2019.