| Abstract [eng] |
The aim of the final master's project is to investigate the reliability of piezoelectric generators of different designs using PVDF films in a cold and heat chamber under different operating conditions. The first part of the master's thesis reviews and compares the piezoelectric materials used in piezoelectric generators and reviews the general structure of the piezoelectric generator. The analysis of the structure of the investigated beam type piezoelectric generator and the methods of PVDF film connection are presented. The methodology used for the longevity testing of piezoelectric generators is reviewed. In the second part of the master 's final project, piezoelectric generators with polyester and steel cores, copper - nickel, aluminum metallization PVDF films are experimentally investigated. Piezoelectric generators are subjected to cyclic thermal and mechanical effects. The effect of thermocycling on the structural stability of piezoelectric generators, the electrical parameters of the PVDF film - the generated voltage, the change of the electric capacitance between the core and the PVDF film electrode, the resistance of the metallized surface are analyzed and evaluated. Ways to improve the structure are discussed and suggested. In the third part of the master 's final project, piezoelectric generators with a polypropylene core and an aluminum-coated polyvinyl fluoride PVDF film are experimentally investigated, the generators initially acting only by thermal cycling. In the next stage, the piezoelectric generators are subjected to thermal and mechanical cyclic effects. The effect of thermocycling on the output voltage of piezoelectric generators, electrical capacitance, mechanical quality factors and resonant frequency changes are analyzed. |
