Flexoelectric Signals on Rings in Transverse Motions Available to Purchase

Dynamic sensing is essential to effective closed-loop vibration control of precision structures and systems. In a centrosymmetric crystal subjected to inhomogeneous deformation, where piezoelectricity is absent, only the strain gradient contributes to the polarization known as the “flexoelectricity.” In this study, a flexoelectric layer is laminated on ring shells to monitor the natural modal signal distributions. Due to the strain gradient, only the bending strain component contributes to the output signal; the total signal has two components respectively induced by the transverse modal oscillation and the circumferential modal oscillation. Analogue to the signal analysis, the sensitivity can also be defined in two forms: a transverse sensitivity induced by the transverse modal oscillation and a transverse sensitivity induced by the circumferential modal oscillation. Analysis data suggest that the transverse modal oscillation dominante the flexoelectric signal generation and its magnitude/distribution shows nearly the same as the total signal. Furthermore, voltage signals and signal sensitivities are evaluated with respect to ring mode, sensor segment size, ring thickness, and ring radius in case studies. The total signal increases with mode numbers and sensor thicknesses, decreases with sensor segment size and ring radius, and remains the same with different ring thicknesses. These data serve as design guidelines to select proper parameters for practical engineering applications using flexoelectric transducers.