Dynamics of Receiving Electroelastic Spherical Shell with a Filler

Numerical calculations of the amplitude-frequency characteristics of the difference of electric potentials at the output of an elastic spherical converter with internal filling were obtained. Vacuum, helium and water were used as the internal filler. Mathematically the operation of the specified oscillatory system is described using the state equations for piezoceramics, which linearly relate components of mechanical stresses, deformations, electrical tensions and induction; the equations of motion of a thin shell involving equations of Cauchy ratios which are connecting components of the strain tensor and the displacement vector; equations of forced electrostatics. The output electrical signal of the investigated spherical receiving transducer with a fully electrode surface is determined by the centrally symmetric component of the stressstrain state of the piezoceramic shell. It is established that the oscillatory system is characterized by the presence of a basic resonance of zero mode and an additional position whose position depends on the electrical load and the characteristics of the aggregate. It is shown that the presence of a filler makes it difficult to match the resistance of the converter with the input resistance of the receiving path and leads to a decrease in the width of its working strip. The resonance is no longer accompanied by antiresonance, as in the case of air or helium filling. Since helium is very similar to air in its characteristics, the frequency response is similar to the frequency response of air. The resonance region accompanied by antiresonance almost coincides in frequency, and the local extremum of the frequency response in the low-frequency region is as weak as in the case of filling the converter with air.