INVESTIGATING MODAL ENERGY REDISTRIBUTIONS IN MECHANICAL SYSTEMS WITH IMPULSIVE STIFFNESS EXCITATION BY USING EFFECTIVE DAMPING MEASURES

摘要

In the present contribution, alternating energy transfers across modes of vibration, induced by impulsive stiffness excitation applied at equidistant instants of time are investigated. Therefore, effective damping measures are used, and it is shown that they clearly indicate modal energy transfers and their effect on the decay rate of transient vibrations. It is demonstrated that outstanding values of the time span between adjacent impulses exist, where a strong energy transfer to higher modes, which possess enhanced damping properties, occurs. Hence, the modal redistribution of vibration energy allows the intrinsic structural damping to be more efficient, resulting in a much faster decrease of vibrations compared to the system without impulsive excitation. It is demonstrated that the effective damping measures provide a proper method to investigate mechanical systems with impulsive stiffness excitation.