Energy-Neutral Transfer of Vibration Energy Across Modes by Using Active Nonlinear Stiffness Variation of Impulsive Type

Abstract

The effect of impulsive stiffness variation to the modal energy content of dynamical systems is investigated in this contribution. Therefore, the overall number of modes of vibration is divided into a set of lower and a set of higher modes. It is shown analytically that impulsive stiffness variation, applied in a state-dependent, nonlinear manner allows a targeted transfer of discrete amounts of energy across mode sets. Analytical conditions are presented, holding for a transfer from the lower to the higher mode set or vice versa. The existence of transfer cases where no energy crosses the system boundary, i.e., the energy-neutral case, is investigated in a comprehensive manner. Some numerical investigations underline that shifting vibration energy to higher modes causes a faster decay of vibration amplitudes, as the damping properties of a mechanical system can be utilized more effectively. Moreover, it is demonstrated that the proposed approach allows to eliminate vibration frequencies from the frequency spectrum of mechanical systems.