Vibration control of slender structures under base motions by pendulum TMD’S

Resumo

The technological progress has been making possible the building of slender constructions, but very
susceptible to unwanted vibrations. To control that, it has been advised the use of TDM’s, that can decrease
considerably the dynamic responses. Following that line, the present work aims to realize a dynamic analysis of a
tall slender tower, exposed to support motions but with a pendular TDM installed to damp out the dynamic effects.
In this work a finite elements model of a 90m tall slim tower without damper is modeled in the Scia Engineer
software, to achieve the natural vibration frequencies, the structure’s equivalent stiffness and mass in the top end.
With those values, a mathematical model with two degrees of freedom is built: the horizontal movement of the top
end of the tower (q1) and the pendulum’s vertical angle (q2). The equations that govern the movement of the
system are derived by the Lagrange Equations. From that model, a program in the Matlab software is introduced
to calculate the structural displacement with and without a tuned pendular mass damper, to verify the dynamic
damper effects, and the displacement limit according to international standards.