Reducing the inductance requirements of piezoelectric shunt damping systems

Structural vibration can be reduced by shunting an attached piezoelectric transducer (PZT) with an electrical impedance. Current shunt circuit designs, e.g. a single-mode inductor–resistor network, typically require large inductance values of up to thousands of henries. In practice, discrete inductors are limited in size to around 1 H. By placing an additional capacitance across the terminals of the PZT, shunt circuit inductances can be drastically reduced. To justify our claims, we present a theoretical analysis of the damped system and identify the influence of the additional capacitance. Two modes of a simply supported beam are successfully damped using a capacitance modified shunt circuit. A low inductance multi-mode circuit is also studied and experimentally verified.