Fatigue behaviour of piezoelectric ceramic stack under large cyclic dynamic loading

Abstract

The fatigue behaviour of a piezoelectric ceramic stack co-fired at low temperatures under the influence of a large cyclic dynamic load was studied. The piezoelectric ceramic stack is equivalent to a parallel plate capacitor with a charge source in parallel. The equations for the total current, output current and capacitor charging current of an equivalent device for an applied load were derived using Kirchhoff’s theoretical formula. A new type of fatigue test equipment was developed for continuous long-term M-shaped wave output. The piezoelectric ceramic stack is positioned between two concrete slabs, forming a pavement-subgrade piezoelectric structure. The fatigue behaviour of the piezoelectric ceramic stack was observed for 800,000 cycles of dynamic load. The results show that the dynamic load studied produced fatigue damage in the piezoelectric ceramic stack. As the number of dynamic loads increased, the electric output capacity of the piezoelectric ceramic stack decreased. Evident stage divisions were observed in the fatigue behaviour of the piezoelectric ceramic stack under cyclic dynamic loading. The electric output capacity of the stack decreased as the number of dynamic loads increased in the early and late stages, whereas it exhibited negligible change during the stable period.