Analysis of global stability of guyed towers considering unilateral constraints

Resumo

Guyed structural systems are present in several engineering applications, and as a large portion of these
structures have a high level of slenderness, their designs are based on stability criteria. The set of cables present in
these elements are characterized by high efficiency when they are tensioned. The main objective of this study is
to analyze the static and dynamic nonlinear behavior of a discrete guyed tower model with two degrees of freedom.
Furthermore, the present work devotes special attention to the consideration of the unilateral contact (boundary
condition) in the nonlinear oscillations of this structure. The unilateral contact is manifested in this type of
application from the consideration of the capacity of the stays to resist only the traction efforts, as an effect, this
approach strongly modifies the analysis of the proposed structural system. For this model, there is a significant
influence of the consideration of unilateral contact on the post-critical behavior, with a marked decrease in the
critical load of the structure. Thus, the results show that this type of structure is highly sensitive to geometric
nonlinearities and to the restriction of certain stays, indicating that these effects must be considered in the tower
design phase.