Parameters design for a non-linear absorber based on phase trajectory analysis

Abstract

The performance of non-linear absorbers for suppression of the structure vibrations depends on the setting of the absorbers' parameters to a certain extent. A slowly varying dynamical system under investigation in the existing work is comprised of a linear oscillator coupled with an attached non-linear absorber called non-linear energy sink (NES). Slowly varying equations of the coupled system are achieved first by using the complex averaging method, and trajectory features of the slowly varying system are analysed. On that basis, the non-linear cubic stiffness design method is proposed. Considering that different damping coefficients of the NES impose a large impact on both system energy transfer and energy dissipation between the main structure and the NES, necessary damping conditions for the targeted energy transfer (TET) are obtained by using the phase trajectory analysis. With the proposed method, structure parameters of the NES are designed to get maximum absorbing effects. Finally, all these conclusions about parameters design for the NES are verified by simulation analysis. The simulation results demonstrate that the optimal vibration reduction effectiveness can be achieved with reasonably designed stiffness and damping.

Keywords

• vibration control
• damping
• oscillators
• structural engineering
• parameters design
• NES
• nonlinear absorber
• phase trajectory analysis
• absorbers
• slowly varying dynamical system
• linear oscillator
• nonlinear energy sink
• coupled system
• nonlinear cubic stiffness design method
• system energy transfer
• energy dissipation
• structure parameters
• targeted energy transfer
• TET