Study on broad flexural wave bandgaps of piezoelectric phononic crystal plates for the vibration and noise attenuation

This paper explores a new approach to reducing the interior noise of one vehicle body through the flexural wave bandgap. The phononic crystal is designed by attaching the periodic piezoelectric stacks with the shunting circuits on the host plate. To better implement the frequency-dependent properties, the theoretical model of the piezoelectric stack is improved through capacitance identification. On this basis, the plane wave expansion method is employed to calculate the bandgap. An ultra-wide bandgap is achieved by tuning the shunting circuits and confirmed via the finite element method. The influence of electrical parameters on flexural wave attenuation is investigated. The applicability of the presented resonators for different host plates under the presented design guideline is examined. Subsequently, the concept of phononic crystal with the unique bandgap is exploited to enhance the interior sound performance of one vehicle body. Combining the sound response analysis with the panel acoustic contribution analysis, the numerical study is performed to pick out the critical panels for the arrangement of resonators. Then a circuit control strategy is proposed to activate the wide bandgap. The results demonstrate that the present piezoelectric phononic crystal plate has a significant advantage in hindering the flexural wave propagation and suppressing structure-borne noise over a broadband low-frequency range. • One phononic crystal plate attached with shunted piezoelectric stacks is designed to achieve the wide flexural wave bandgap. • The dispersion theory is applied to calculate the bandgap based on the improved theoretical model of the piezoelectric stack. • The guideline for the ultra-wide bandgap is presented and the bandgap properties are parametrically investigated. • The wide bandgap and the circuit control strategy help suppress the vibration of the panel and the vehicle interior noise.