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COBEM 2023
27th International Congress of Mechanical Engineering
2-DOF discrete model for non-linear vibrations analysis of guyed towers considering unilateral contact cables
Submission Author:
Frederico Martins Alves da Silva , GO , Brazil
Co-Authors:
Fernanda Silva, Frederico Martins Alves da Silva
Presenter: Frederico Martins Alves da Silva
doi://10.26678/ABCM.COBEM2023.COB2023-1373
Abstract
Guyed structural systems are commonly used in different engineering areas, but their designs are heavily dependent on stability criteria due to their high slenderness ratio. The cables used in these structures are highly efficient when tensioned, which allows them to absorb a significant portion of the loads acting on the structures. However, accidents involving cable-stayed towers are not uncommon, with cable rupture being a frequent cause of structural failure. In this study, we aim to analyze the statical and dynamical nonlinear behavior of a discrete plane guyed tower model by a two degrees of freedom model. We also pay special attention to the effect of unilateral constraints on the nonlinear displacements of the guyed tower. Unilateral constraints are critical in this type of application as they affect the capacity of the stays to resist only the tensile efforts, which modifies the statical and dynamical analysis of the proposed structural system. To account for geometric nonlinearity, we define the equilibrium equations by observing the deformed configuration equilibrium under the action of external loads and prestressing in the cables. We carry out a parametric analysis of the influence of the unilateral contact of the stays on the critical load, the post-critical behavior, and in the nonlinear vibrations. Our findings reveal a significant influence of the consideration of unilateral constraints on the statical and dynamical stability of the model, leading to a marked decrease in the critical load of the structure and changing the dynamical bifurcation diagrams, suggesting that geometric nonlinearities and the restriction of the contact of stays significantly affect the nonlinear behavior of this type of structure, and these effects must be taken into account in the design step.
Keywords
nonlinear dynamics, Guyed Tower, unilateral contact
