Vibration power flow characteristics of the whole-spacecraft with a nonlinear energy sink

The power flow analysis approach is applied for quantitatively evaluating the dynamic performance of a nonlinear energy sink in the frequency domain. A two-degree-of-freedom model of the whole-spacecraft coupled to a nonlinear energy sink is considered. Analytical approximations and numerical integrations are performed for the integrated system. The time-averaged input and dissipated and absorbed powers of the system are formulated. Power absorption ratio is proposed as the vibration reduction performance indicator of the nonlinear energy sink and is compared with kinetic energy of the oscillator. Results show that the power absorption ratio of nonlinear energy sink is high at all frequencies except at an antiresonance region. The effects of varying nonlinear energy sink parameters on its vibration absorption performance are discussed. As observed, the nonlinear energy sink performs well with the increase in viscous damping of nonlinear energy sink in the high-frequency range. However, the nonlinear energy sink performs poorly in the low-frequency range in the same case. Therefore, power flow analysis can provide great insight for nonlinear energy sink design in frequency domain and is suitable for practical engineering application.