Power Harvesting Prediction of Piezoelectric Stack Actuator From a Shock Event

Abstract

In this study, the power harvesting performance of a piezoelectric (PZT) ceramic multilayer stack actuator under a shock event is theoretically and experimentally investigated. The model is derived from the constitutive - 33 mode equations under single degree of freedom (SDOF) assumptions, and then a correction factor is applied onto the resulting electromechanically coupled governing equations. These are represented in state space form and solved in the numerical computation software MATLAB. In order to achieve experimental validation, two test cases are compared to the model prediction when impulses of 20.8 mN·s and 1.70 mN·s are loaded on to the PZT stack actuator. The voltage and power output between the model and the test cases matched well. For the first case, the PZT stack actuator harvested 0.3321 μJ from the shock event while the model’s prediction was 0.3358 μJ, which results in a percent error of only 1.1%. In the second case, the PZT stack actuator harvested 34.64 nJ from the shock event while the model’s prediction was 35.80 nJ, which results in a percent error of 3.2%. This paper achieves its objective of deriving a model that can accurately predict the power harvested when an impulse load is applied onto a PZT stack actuator, and then validating this model with testing.