Synthetical vibration reduction of the nonlinear acoustic metamaterial honeycomb sandwich plate

Light-weight and high-stiffness honeycomb sandwich plates are widely used in high- speed vehicles. Suppressing their low-frequency and broadband vibration is significant for improving safety and reducing noise, but remains challenging with limited mass cost. Bandgaps and chaotic band in nonlinear acoustic metamaterials (NAMs) offer an effective way for vibration reduction. This paper conceives a NAM sandwich plate and studies its vibration reduction properties based on numerical and experimental methods. We establish its nonlinear finite element model based on the equivalent homogeneous model and experiments. The influences of the resonator distribution, nonlinear stiffness, resonant frequencies, mass, amplitude and structural plate parameters on its vibration are thoroughly analyzed to achieve the best performance. Then, we manufacture an optimized NAM plate and experimentally demonstrate that all resonances of the high-stiffness NAM plate below 800 Hz are greatly reduced with only 17.7 % attached mass; particularly, the first low-frequency resonance at 93 Hz is reduced by 20 dB. This shows that the NAM strategy can robustly and effectively suppress the low-frequency and broadband vibration of the light-weight and high-stiffness plates with small mass cost, a synthetical performance desired for broad potential applications. The models, regularities, designs and experiments can also enlighten more studies on relate topics.