SUPRATRANSMISSION HYSTERESIS AND NONRECIPROCAL CODES IN A PIEZOELECTRIC METASTRUCTURE WITH BISTABLE-CIRCUIT SHUNTS

It is able to achieve novel properties of vibration transmission by utilizing the nonlinear effects of metastructures. Bistable metastructures are known to possess the nonlinear supratransmission behavior, which states that in the linearized bandgap of metastructures, the transmitted vibration energy increases sharply when the excitation amplitude reaches a certain threshold. In this paper, the electrical-mechanical coupling numerical model is established for a piezoelectric metastructure with bistable-circuit shunts, the model order of which is further reduced by using the Galerkin method for improving the computation efficiency. With the achieved dynamic model, we investigate the nonlinear properties of vibration transmission through the bistable piezoelectric metastructure. It is found that, in the local-resonance bandgap of the linearized metastructure around stable equilibria, the supratransmission thresholds exhibit distinctions when the excitation amplitude sweeps up versus down, indicating the emergence of a hysteresis effect in supratransmission. The supratransmission hysteresis range can be effectively shifted through adjusting the distance between the two stable equilibria or weakening the resonance intensity of circuits around them. Furthermore, it is observed that by configurating linear resonant circuits on one side of the metastructure to introduce a system asymmetry, the supratransmission hysteresis ranges of the forward and backward directions deviate away from each other. This nonreciprocal hysteresis effect enables appearance of different patterns of nonreciprocal codes in the metastructure, which can be tuned by altering the excitation amplitude. The deviation of the forward and backward supratransmission hysteresis ranges can be improved if a larger system asymmetry is used, making this sort of nonreciprocal codes adaptive. Overall, this research extends the nonreciprocity patterns of conventional metamaterials, which is not limited to the settled “transmission” or “non-transmission” states of elastic wave in the two opposite directions. The deliberately designed elastic binary codes can be seen as a sort of elastic information. Therefore, this research also opens up possibilities for achieving unidirectional transmission of elastic information.