Design Considerations for Optimal Absorption of Energy from a Vibration Source by an Array of Harvesters

Abstract

Dynamic vibration absorption is a passive technique for suppressing unintended vibrations. Optimal absorption of energy from a vibration source entails the determination of absorber parameters such as resonant frequency and damping. In the present work, we propose a method to obtain these parameters for a generic case of large number of identical vibration absorbers placed on a vibration source. We discuss an iterative procedure to find the optimum absorber resonant frequency and damping by minimizing the total energy absorbed by the system. We also analyse the influence of damping of the entire set of absorbers on the total energy absorbed and the effect of the absorber mass on the bandwidth of absorption. The proposed method is verified by analysing the response of a set of cantilever absorber beams placed on a vibrating cantilever plate. The resonant frequencies of the system with different number of absorbers are verified experimentally. We identify, using our method, the absorber mass, resonant frequency and damping of the absorber at which significant amount of energy supplied to the system flows into absorbers. A potential application of this method in the context of energy harvesting is the design of harvesters for a given vibration source. We emphasize through our work that monitoring energies in the system and optimizing them is both rational and vital for designing multiple harvesters that absorb energy from a given vibration source optimally.