Nonlinear Response of the Macro Fiber Composite Actuator to Monotonically Increasing Excitation Voltages

Abstract

This paper presents a nonlinear model which predicts the response of a piezoelectric continuum to a monotonic increase in electric field from some DC offset value under some constant mechanical load within the linear-elastic region. A general model is derived and then specialized for a piezoceramic-based material with anisotropic actuation and mechanical properties, for example, the Macro Fiber Composite (MFC) actuator. This specialized formulation includes the linear-elastic mechanical response, as well as linear and second-order piezoelectric behavior and a second-order electromechanical cross term. Thus, there are many required linear and nonlinear material parameters, namely the elastic compliances, piezoelectric strain coefficients, electrostrictive, and elastostrictive coefficients. Using previously published work dealing with the mechanical response of the MFC [1], this rather large set of material properties is determined experimentally in order to predict the response of the Macro Fiber Composite device to given external loading conditions.