Bazilo C. Theory of constructing the piezoelectric disk transducers with separated electrodes for critical application computer systems

The thesis is devoted to solving the actual scientific and applied problem of creating highly efficient piezoelectric transducers for critical application computer systems while simultaneously increasing the degree of integration and hybridizing of operational properties by creating new and improving existing models and methods of synthesis of piezoelectric transducers with separated electrodes. The mathematical model of the electrical impedance of piezoelectric disk oscillating in a wide frequency range was improved, and on this basis, a method for the experimental determination of the material constants of piezoceramics was developed. This method, unlike the known ones, allows in one experiment to determine three elastic moduli, two piezomoduli and one value of dielectric constant to obtain reliable quantitative estimates of physical state parameters of disk piezoelectric transducers. For the first time, mathematical models of piezoelectric transducers with ring and disk electrodes in primary electrical circuit and multisectional disk piezoelectric transducers with the possibility of group connection of sections taking into account negative electroacoustic feedback and electric load impedance values were developed. These expands the possibilities of constructing multifunctional piezoelectric transducers for critical application computer systems. For the first time, a mathematical model of disk piezoelectric transducer with sector electrodes, constructed with a minimum number of assumptions that simplify the real situation, was developed. These allows predicting the characteristics of the transducer operating on non-axisymmetric planar oscillations. The mathematical model of bimorph piezoelectric transducer with symmetric electrical load in the secondary circuit was improved. This, based on fundamental principles of mechanics and electrodynamics, allows to take into account the geometrical, mechanical and electrical parameters of the real design of piezoelectric transducer, the principle of which is based on the use of axisymmetric bending oscillations. Methods for modifying disk piezoelectric transducers for critical application computer systems by using a polyelectrode design, additional element technology, spatial energy-power structure of piezoelectric transducers received further development, which makes it possible to synthesize piezoelectric transducers with improved characteristics. Keywords: computer system, critical application object, piezoelectric transducer, disk piezoelectric element, modification methods, synthesis, output characteristics.