A Synthetic Shunt for Piezoelectric-Based State Switching

Piezoelectric-based state switching selectively switches between available stiffness states. Some state switching methods require switching from a high-to low-stiffness state at points in the vibration cycle of non-zero strain, resulting in a rapid dissipation of the stored piezoelectric voltage, and a corresponding rapid variation in the system stiffness. This manner of switching induces high-frequency, large-amplitude mechanical transients that are unavoidable and is analogous to an impact, where increasing the switch duration reduces the range of modes excited. Recent develops show that controlling the duration of the voltage dissipation by means of a resistor in the shunt circuit significantly reduces these induced transients; however, incorporating a resistor in the shunt can introduce damping which may be undesirable, depending on the application. As such, this paper numerically investigates an alternate method of controlling the duration of the switch via a variable capacitance shunt.