High Frequency Time Varying Resistive Shunting of Piezoceramic Transducers

摘要

Potential and more popular applications of piezoceramics are in the field of active vibration control. However, the objective of this study is to investigate the effect of shunted pieszoeramics as passive vibration control devices when bonded to a host structure. Resistive shunting of a piezoceramic bonded to a cantilevered duralumin beam has been investigated. The effect of resistive shunting on the nature of damping enhancement to the host structure has been investigated. An increase of 60% in loss factor and one percent shift in natural frequency is observed due to time-invariant resistive shunting at optimal resistance. High frequency excitations to structure lead to stiffening effects. The stiffening behaviour of such system is realized by partitioning the beam dynamics into fast and slow motions. The effect of fast motion on slow dynamics is determined by averaging out the high frequency motion due to high frequency excitation. Based on this concept, apart from time-invariant resistance across the piezoceramics, the effect of frequency and amplitude of high-frequency time varying resistance are examined in terms of increase in damping and damped natural frequencies of the beam in slow flexural dynamics. The improvement in terms of added damping or change in damped/or undamped natural frequencies due to time varying resistance is marginalin comparison to constant time-invariant resistance.