Energy harvesting dynamic vibration absorber under random vibration

Energy harvesting from structural vibration using piezoelectric material has received much attention in the past few years. The idea is to scavenge energy out of a vibrating host. Coupling energy harvesting with structural vibration control is a challenging task due to conflicting goals. But dynamic vibration absorbers (DVA) used to reduce vibrations in the primary structure has potential for energy harvesting capability. In this mechanism the host structure vibration is reduced by suitably shifting the motion to DVA. Vibration energy in DVA can be harvested. The harvested energy can be used to power low-powered wireless sensor systems. This paper analyses the prospect of using vibration absorbers for possible energy harvesting under random excitation. To achieve this goal, vibration absorber is supplemented with a piezoelectric stack for both vibration confinement and energy harvesting. The primary goal is to control the vibration of the host structure and the secondary goal is to harvest energy out of the dynamic vibration absorber simultaneously. It is shown that with a proper choice of harvester parameters a broadband energy harvesting can be obtained combined with vibration reduction in the primary structure. Analytical studies are carried out considering stationary Gaussian white noise excitation within the frequency band of interest. Finally a single storey building under seismic excitation is considered and numerical results of structural control and energy harvested are shown.