Electromechanical response of multilayer piezoelectric actuators for fuel injectors at high temperatures

This paper studies the electromechanical response of multilayer piezoelectric actuators from room to high temperatures for fuel injector applications. A phenomenological model of depolarization at high temperatures was proposed, and the temperature dependent piezoelectric coefficients were obtained. The nonlinear electromechanical fields of the multilayer piezoelectric actuators due to the depolarization at high temperatures were then calculated by the finite element method. In addition, experimental results on the electric field induced strain at high temperatures were presented to validate the predictions.