A COMPARISON OF A NON-LINEAR PENDULUM ABSORBER 2D AND 3D

Resumo

Designed to reduce the vibrations amplitudes in the horizontal direction of slender structures and
industrial components subjected to dynamic excitations, such as wind and earthquakes, a non-linear pendulum
control system is assessed in this paper. Firstly, 2D and 3D mathematical models are developed based on the
Lagrange’s energy equations. The system of non-linear differential equations of motion is numerically solved in
time domain. Some parametric studies are performed to understand the role of some key physical characteristics
of the control device in its effectiveness in controlling the vibration amplitudes of a structure under certain load
scenarios, including the pendulum mass, damping ratio and length. Finally, the results obtained with two
perpendicular 2D simplified pendulum model is compared to the results obtained with the 3D pendulum model in
order to evaluate the performance in the use of the simplified approach to design this type of passive control
system.