Dynamic instability of cable stayed masts

Resumo

Cable stayed structures are widely used in several engineering areas such as civil, mechanical,
telecommunications and offshore engineering. These structures are light weight and efficient to carry both axial
and lateral loads due to the stayed cables and can be characterized by large displacements and high load bearing
ratios. As these structures can display large displacements which are associated to both nonlinear static and
dynamic behavior, the research of its nonlinear response is of high interest by engineers and scientists. In this
work, the dynamic instability of cable stayed masts is studied. For this, the mast is described as a simplified
nonlinear one degree-of-freedom system subjected to a lateral harmonic load. The Hamilton principle is applied
to obtain the nonlinear dynamic equilibrium equation which is solved using the 4th order Runge-Kutta method. A
parametric detailed analysis is considered to obtain the time response, Poincaré maps and resonance . Obtained
numerical results show the great influence of both cable tensioning and cable positioning on the non-linear
behavior of the system and could be used as a tool for an analysis of the nonlinear dynamics of the structure
previous to design.