Analysis and experimental evaluation of a new planar piezoelectric accelerometer

In this paper, the behavior of a new planar piezoelectric accelerometer is investigated, both theoretically and experimentally. The proposed accelerom eter is composed of a piezoceramic ring filled, in its inner space, with a seismic mass. The theoretical analysis has been carried out by using a matr ix model of the radial symmetric modes of the thin piezoceramic ring, recen tly proposed by the authors. The numerical results obtained for the empty r ing show that, the response being constant, the bandwidth increases when th e annulus radius increases. On the contrary, by inserting a high-density an d stiffness seismic mass, both the response and the bandwidth increase by i ncreasing the percent quantity of the seismic mass. The measurements of adm ittance and sensitivity, carried out on a test specimen, validate the compu ted results and demonstrate that the accelerometer is planar, i,e,, it is a ble to detect the mechanical excitation from any radial direction, independ ently of the azimuthal angle. Finally, an accelerometer composed by two of such elements, stacked and connected in parallel, has been realized. It has shown a sensitivity quite hat and of appreciable value in a very wide freq uency range.