A material rigidity effect of a bimorph piezoelectric actuator

Abstract

This paper presents the numerical modeling of a piezoelectric actuator used to avoid the limitation of the lock-in region in a ring resonator. Ring resonators have proved suitable for use as inertial sensors for navigation, guidance and attitude controls. However, their accuracy has been limited by the lock-in region due to frequency coupling between two counter-propagating waves at low rotation rates. This coupling introduces no phase difference, and no angular increment is detected. The problem can be overcome by mechanically dithering the ring resonator. Mechanically, the vibro-elastic bimorph piezoelectric actuator has been used as a control but is influenced by piezoelectric rigidity effects. To more accurately predict the dithering frequency of a mechanical dither, numerical modeling of a piezoelectric actuator includes the piezoelectric rigidity effect of the actuator, which occurs in both the static and dynamic behaviors of composite plates having piezoelectric layers symmetrically bonded to the top and bottom surfaces.