Active acoustic metamaterial structural unit and control device thereof

Abstract

The present invention provides an active acoustic metamaterial structural unit and a control device thereof, belonging to the technical field of acoustic metamaterials. The objective of the inventionis to provide an acoustic metamaterial structural unit with a function for active regulation of an inherent frequency and a control device thereof. The technical scheme employed to solve the technicalproblem comprises an active acoustic metamaterial structural unit, the active acoustic metamaterial structural unit comprises a rigid frame, at least one cantilever beam and a concentrated mass block, the concentrated mass block is located in the rigid frame, the concentrated mass block is fixedly connected with the rigid frame through the at least one cantilever beam, and the at least cantileverbeam employs elastic materials, the at least cantilever beam is internally provided with a cavity with a gas nipple. The control device of the active acoustic metamaterial structural unit comprises an active acoustic metamaterial structural unit, a microphone, a data collection card, a computer, a regulation valve, a gas storage tank, a pressure transmitter and a flow divider. The active acousticmetamaterial structural unit and the control device thereof can be widely applied to the field of noise inhibition.

Description

technical field [0001] The invention relates to an active acoustic metamaterial structural unit and a control device thereof, belonging to the technical field of acoustic metamaterials. Background technique [0002] The band gap based on local resonance is caused by the interaction between the resonance of the acoustic metamaterial structural unit itself and the propagation of elastic waves in the structure. Most of the existing acoustic metamaterial structural units can be equivalent to low-frequency dipole harmonic oscillators. : The film or other support structure is equivalent to the spring, and the mass block is equivalent to the mass connected to the spring; the matrix is ​​connected to the other end of the vibrator spring, which transmits the incident vibration and provides an environment for coupling with the surrounding structural units. When approaching the resonant frequency of the structural units, the incident acoustic wave is strongly resonantly scattered by th...

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Problems solved by technology

The adjustment methods of the above-mentioned acoustic metamaterials often require complex auxiliary devices, such as high-voltage generating devices and huge magnetic force generating devices and mechanical deformation adjustment devices.

Moreover, the existing technology only verifies the influence of certain parameter changes on the noise suppression effect in principle, but does not build a complete active adjustment system to realize adaptive parameter adjustment. Therefore, in the field of noise control of vehicles and aircraft, there is often a lack of feasible sex

[0006] The cantilever beam of the existing acoustic metamaterial structure is a solid structure, does not have a cavity, and cannot adjust the stiffness of the system, so its natural frequency has a single value and has narrow-band characteristics. When the noise frequency w Deviating from the natural frequency of the metamaterial w 0 , the structure no longer resonates, and the effect of converting acoustic energy into kinetic energy decays rapidly, indicating that the existing acoustic metamaterials no longer have the ability to suppress noise with non-intrinsic frequency components.

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