Modeling hysteresis and creep behavior of macrofiber composite–based piezoelectric bimorph actuator

Macrofiber composite–based bimorph actuators inherit the nonlinear properties of hysteresis and creep of piezoelectric materials, which limit the accuracy in real-time control. Many hysteresis models have been proposed, and generalized Maxwell slip model consisting of a series of nonlinear elements is one of the simplest and most efficient operators to describe symmetrical hysteresis. However, these hysteresis operators do not contain the creep behavior of piezoelectric materials. In this study, a hybrid model including a generalized Maxwell slip operator, a creep operator, and a dynamic model is developed to characterize a macrofiber composite–based piezoelectric bimorph actuator. The generalized Maxwell slip operator is used to describe the hysteresis, the creep operator is used to describe the creep behavior, and a transfer function is used to describe the dynamic model. Each nonlinear element in the creep operator is made up of a diode, a resistance, and a capacitance. The experiment results show that the proposed model can accurately predict the hysteresis, creep, and dynamic behaviors of the macrofiber composite–based piezoelectric bimorph actuator.