Voltage-dependent modulation of effective Young?s modulus and shape in piezoelectric composite metamaterials

This article presents the voltage-dependent elastic properties of the novel piezoelectric composite metamaterials (PCMs). The angular rib of PCM consists of the bimaterial beam. Therefore, the deformation of bimaterial beam controlled by the applied voltage and stress affects the behavior of the PCM. It is possible to actively modulate the strain and Young's modulus by adjusting voltage. The effects of re-entrant angle and thickness of piezo-electric beam on their elastic properties are characterized. Considering the bending deformation of bimaterial beam based on the unit cell, the expression of voltage-dependent strain and equivalent Young's modulus are derived. A simplified model based on Euler-Bernoulli beam theory leading to the expression is derived for PCM. The finite element analysis of the mentioned structures is developed. And the correctness and validity of the closed-form analytical expressions in this paper are verified by comparing the numerical results with the analytical results. The results show that voltage-dependent Young's modulus of the PCM can be adjusted in a certain range by applying external voltage. And different elastic properties of the PCM can be shown in various combinations of re-entrant angle and thickness of piezoelectric beam.