介电弹性薄膜吸声体的可调频率试验分析  

Experimental Analysis of Frequency Adjustable Dielectric Elastomer Membrane Sound Absorbers

作　　者：周伟青 吴锦武[1] 陈杰 ZHOU Weiqing;WU Jinwu;CHEN Jie(School of Aircraft Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学飞行器工程学院,南昌330063

出　　处：《噪声与振动控制》2021年第6期205-210,共6页Noise and Vibration Control

基　　金：国家自然科学基金资助项目(51965041);江西省研究生创新专项资金资助项目(YC2019-036)。

摘　　要：利用介电弹性薄膜的电致动特性,设计一种可调频率的吸声体结构。该结构由介电弹性薄膜与空气背腔组成,通过调节施加在薄膜上电压大小改变其内应力,从而可使得薄膜吸声体的固有频率与吸声系数峰值对应频率发生偏移。实验结果表明:介电弹性薄膜吸声体固有频率随电压升高而降低,吸声系数各个峰值对应频率随电压增大均向低频偏移;背腔主要影响吸声系数大小,但对吸声系数峰值对应频率影响很小。通过对比其吸声系数峰值与比较模态振型可知,只有平均位移大于零的模态振型才对吸声性能有贡献。A frequency adjustable sound absorber is designed based on the electrodynamic characteristics of dielectric elastomer(DE).The structure is composed of a DE membrane and an air cavity.The internal stress can be changed by adjusting the voltage applied on the membrane.Then the natural frequency and the peak of sound absorption coefficient of the membrane can be changed.The experimental results show that the natural frequency of the DE membrane absorber decrease with increasing of voltage.Meanwhile,all of the peaks of the sound absorption coefficient shift towards lower frequency with the increase of voltage.In addition,it can be observed that the depth of cavity mainly influences the absorption coefficient value,however has very little effect on the corresponding peak frequency of the sound absorption coefficient.By comparing the peak frequencies of the absorption coefficient and the modal shapes,it is obviously found that only the modal shapes with positive average displacement have the contribution to the sound absorption performance.

关 键 词：振动与波 介电弹性体 可调吸声频率 吸声 

分 类 号：TB535[理学—物理]