Investigating the robustness of nonlinear energy sink in steady state dynamics of linear beams with different boundary conditions

Steady state dynamics of damped linear harmonically excited beams coupled to a single degree of freedom (DOF) nonlinear energy sink (NES) with nonlinear stiffness of order three is studied. By varying different parameters of the nonlinear absorber, a set of optimized parameters is obtained. Robustness of the optimized NES against changes in the amplitude of the excitation force is investigated. Since vibration amplitude of a nonlinear system is dependent on the amplitude of excitation force, robustness of the designed NES is low. Results illustrate that designing NES for the maximum possible forcing amplitude leads to great amount of vibration reduction not only for the designed force but also for lower values of forcing amplitude. With this strategy, robustness of the designed NES can be improved significantly.