| Textile materials have always been important sound absorption and noise reduction materials.Especially in recent years,based on the rapid improvement in the performance requirements of decorative textiles,how to improve its sound absorption performance has become one of the important research directions.The main research object of this paper is woven fabric,an acoustic material with good structural design and dimensional stability.The main purpose is to reveal the influence of pore structure,surface structure and attachment structure on the sound absorption performance of woven structural textiles through testing and analysis,so as to provide guidance for the design of sound absorption and noise reduction performance for wall coverings and wall-mounted materials for vehicles,high-speed rail and other vehicles and broaden their applications in the fields of noise control and room acoustics.In order to study the effect of pore structure on the sound absorption performance of woven fabrics,seven woven fabrics with different porosities were used as substrates,and two-layer and three-layer structures were constructed by changing the pore gradient direction,pore gradient difference and lamination angle.The results show that the collocation of the pore parameters along the sound wave propagation direction has an important influence on the sound absorption performance of the structure.When the porosity difference between the double-layer fabrics is9.75%,the acoustic impedance of the structure with different pore gradient directions is the same.When the porosity difference is less than 9.75%,the double-layer structure with porosity arranged in the direction of sound wave propagation in order from large to small has a better sound absorption effect.When the porosity difference is more than 9.75%,the double-layer structure with porosity arranged in the direction of sound wave propagation in order from small to larger has a better sound absorption effect.The three-layer structures also verified this rule.In addition,the sound absorption performance of the three-layer fabric arranged in the order of porosity from small to large to small is better than that of large to small to large,even though the thickness of the former is smaller.The change of the lamination angle will affect the sound absorption performance of the structure.Among the three lamination angles of 0°,45° and 90°,the sound absorption effect of the double-layer structure is better at90°.The influence of fabric surface structure on sound absorption performance was investigated.Studies have shown that the sound absorption performance of the fabric is related to the surface roughness of the fabric.Ordinary woven fabrics and flannels all follow the rule that the greater the roughness,the greater the sound absorption performance after excluding the influence of their own density or square meter weight,except for a few samples.On the basis of considering both microporous sound absorption and resonance sound absorption,the fabrics in both cases of glued and uncoated were combined with the thin air layer respectively,and the influence of the thickness of the air layer,the fabric structure and the glial layer on the sound absorption performance of the structure was discussed.As a result,the addition of the air layer will increase the sound absorption performance of the fabric.As the thickness of the air layer increases,the frequency corresponding to the peak of the sound absorption coefficient of the material gradually shifts to the low frequency.In the sound-absorbing structure formed with a thin layer of air,the thicker the fabric,the better the sound-absorbing effect.The addition of the glue layer can significantly improve the sound absorption effect of the structure,the sound absorption performance of thicker fabrics can be greatly improved after coating in the low frequency range of 1000-3000 Hz. |
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