一种镶嵌薄膜共振型材料的吸声性能研究

Study on the Sound Absorption Property of an Resonance-type Material Decorated With Membrane

为了解决现有吸声材料对低频噪声衰减弱及吸收差的现状,该文提出了一种镶嵌薄膜共振型材料结构。其中镶嵌到条形薄膜上的结构单元作为拍动体,此时结构单元与背衬薄膜之间存在一定耦合作用,使行波在两部分间的局域共振作用削弱或存在很少反射。通过有限元仿真分析得到吸收峰值下的模态振型,进一步证明了材料的吸声机理。实验表明,该结构对100~1 000Hz内的声波具有很好的吸收效果,单层材料结构随着空腔距离的增大,吸收峰提前,而峰值基本不变。两层材料结构的吸声效果远大于单层材料结构,这解决了低频噪声问题。

Aiming at the problem of small attenuation and not good absorption at low frequency sound noise,a resonance-type material structure decorated with membrane is proposed in this paper.The structure unit of elastic membrane decorated with relatively rigid platelets is used as the flapping body.The coupling action between the structure unit and the back-decorating membrane exists,thus the local resonance of the traveling wave between the two pars is weakened or hardly reflected.The complex structure is analyzed by finite element method(FEM)and the mode of vibration is obtained at absorption peaks,the sound absorption mechanism of material structure is further investigated.The experiments indicate that the structure shows the sound absorption property well in 100~1 000 Hz,the cavity distance is more and more increased,the single-layer material structure have advanced absorption peaks and the peak value is fundamentally not changed.The sound absorption property of the double-layer material is far better that of the single-layer material,and the problem of low frequency sound noise is thoroughly solved.