ANALYSIS OF CREEP VISCOELASTIC MECHANICAL BEHAVIOR IN BEAMS USING THE FINITE ELEMENT POSITIONAL FORMULATION
Juliano dos Santos Becho1; João Marcos Guimarães Rabelo1; Paulo Gonçalves Jr. De Oliveira1; Felício Bruzzi Barros1; Marcelo Greco1
1 Universidade Federal de Minas Gerais
doi:10.20906/CPS/CILAMCE2015-0579
Resumo
The present work addresses the issue of the nonlinear numerical analysis of beams with creep viscoelastic behavior. The numerical strategy adopted is the Finite Element nonlinear positional formulation, taking into account the classic theory of Bernoulli-Euler. The geometrical nonlinearity represented by the structural equilibrium in the deformed position is solved using the Newton-Raphson method. The physical nonlinearity refers to the adoption of a rheological relation to describe the viscoelastic behavior, deduced from a uniaxial rheological model based on the generalized Maxwell model. The formulation is fitted by using the creep results of uniaxial tension tests on Glass Fiber Reinforced Plastic, obtained from the literature. This is achieved by the parametrization of the height of the cross section is adopted, which provides an idealization of the beam as bundled bars. Then the presented formulation is used to analyze a beam with different boundary conditions. The results are used to compare the elastic and viscoelastic behaviors of the beam and to demonstrate the representative capacity of the phenomenon with the adopted formulation and fitting approach.
Palavras-chave: Viscoelasticity; Creep; Positional Formulation; FEM; Rheological Model