【摘要】 针对低频噪声较难控制的问题,设计一种基于电磁力调谐的薄膜主动声学超材料,该结构由通电螺线管和边界固定、中心附加钕铁硼磁铁的薄膜等结构组成。通过数值模拟和实验对其声学性能进行详细分析,结果表明:该结构具有较好的低频隔声性能。通过输入大小不同电流使螺线管内产生不同强度的磁场,从而定量改变薄膜中心钕铁硼磁铁受力,实现隔声峰值频率的定向移动,与被动式声学超材料相比,可实现声学超材料隔声特性的非接触式主动控制;在此基础上进一步研究薄膜厚度和薄膜杨氏模量对结构隔声性能的影响。更多还原

【Abstract】 Aiming at the difficulty of low-frequency noise control, a membrane-type active acoustic meta-material based on electromagnetic force tuning is designed. The structure of the meta-material consists of a power-supply solenoid and a membrane with an NdFeB magnet at the center. The acoustic performance of the membrane is analyzed in detail by numerical simulation and experiment. The results show that the structure has a good low-frequency sound insulation performance. By inputting different currents, different magnetic fields are generated in the solenoid and the force magnitude of the NdFeB magnet at the center of the membrane can be adjusted to realize the directional shift of the sound insulation peak frequency. Compared with the passive acoustic meta-material, this meta-material can realize the non-contact active control of the sound insulation. On this basis, the influences of the thickness and Young’s modulus of the membrane on the sound insulation performance of the structure are studied.更多还原