RESEARCH ON ACTION BEHAVIOR OF MACRO FIBER COMPOSITES APPLIED IN CANTILEVER STRUCTURES

Macro fiber composite (MFC) is a new kind of piezoelectric material with excellent performances developed by NASA Langley Research Center. An accurate understanding of the mechanical behavior of MFC helps to apply it to structural deformation control, vibration control, noise reduction, health monitoring and other fields. However, there are few researches on the macroscopic mechanical behavior of MFC in the literature, especially about the relationship between the actuating force and the voltage. The limited accuracy of the relationship between the actuating force and the voltage is not conducive to apply MFC to more precise application scenarios. In the present paper, the actuation equation of MFC acting on a cantilever structure is derived by considering the relative dimensions of MFC and the controlled structure to overcome this problem based on classic plate theory. For sake of the balance of the accuracy and convenience for the simulation, a detailed finite element model considering the bending electric field of the interdigitated electrode of MFC is established to carry out piezoelectric-static simulation. A correction coefficient is introduced for simplifying the electric field of the interdigitated electrode. A piezoelectric-static experiment is carried out to validate the finite element model and the actuation formula for a MFC-cantilever beam. The simulation results of the detailed model and the simplified model are compared with the experiment. The relative error between the simulations and the experiment is little, which verifies the reliability of the model and the correction coefficient of the curved electric field. The correctness of the theoretical analysis is verified by the simulation results, which indicates the actuation prediction formula has a good precision in a wide range of width ratio between MFC and the controlled structure. The actuating model of MFC established in this paper has a certain guiding significance for the application of MFC to the deformation control and vibration suppression for cantilever structures.