Dynamic thermo-electro-mechanical performance of piezoelectric stack actuators

Abstract

Piezoelectric actuators are increasingly used in modern fuel injectors due to their quick response, high efficiency, and excellent repeatability. Current understanding of the thermo-electro-mechanical performance of piezoelectric actuators under dynamic driving fields is very limited. In this paper, the dynamic thermo-electro-mechanical performance of Lead Titanate Zirconate (PZT) stack actuators is experimentally studied over the temperature range of -30 °C to 80 °C, under a driving field of up to 2.4 kV/mm (with an AC drive method) and a constant preload of about 5MPa. Sinusoidal and trapezoidal driving fields with rise times varying from 0.1 ms to 2 ms are applied. It is found that dynamic stroke increases steadily with the temperature. Under driving frequencies lower than the resonance frequency of the testing system ( ≈ 500Hz), the electric field-strain behavior under different temperatures is very similar to the quasi-static results obtained previously. In the case of a trapezoidal pulse, decreasing the rise time is found to be equivalent to increasing the frequency.