Design of a nonlinear absorber for a 2 degrees of freedom pendulum and experimental validation

Abstract

A nonlinear energy sink is designed to control the oscillations of a 2 degreesof-freedom pendulum under the following types of excitations: horizontal and vertical base displacements and initial energy. Coupled nonlinear governing system equations are treated with the multiple-scale methods with different assumptions depending on applied loads. Fast and slow system dynamics are revealed leading to detection of different possible dynamical regimes. The choice of the design parameters of the nonlinear energy sink is discussed, and a tuning method is proposed. The efficiency of the control is validated by an experimental study: a physical model of the pendulum is excited by the shake table. The response of the system shows that the nonlinear energy sink is able to control the main system.

Nonlinear vibratory energy exchanges in a meta-cell

“…The NES in its early developments was composed of a cubic nonlinear restoring forcing function [17]. Then, other types of nonlinearaties were exploited for designing the NES: i) nonsmooth systems including vibro impact [19,20,21], piece-wise linear [22,23,24] and Bouc-Wen type [25]. Such systems have been applied in many domains such as mechanics and acoustics, with applications in aeroelastic domains [26,27,28,29,30], structural engineering [31,32,33] and noise control [34,35].…”