文献类型：期刊文献

中文题名：木质阻尼复合结构中填充多孔材料的隔声性能分析

英文题名：Analysis of Sound Insulation Performance of Porous Materials Filled in Wood Damping Structures

作者：刘美宏[1] 彭立民[1] 樊正强[1]

第一作者：刘美宏

通信作者：Peng, Limin

机构：[1]中国林业科学研究院木材工业研究所

年份：2019

卷号：55

期号：6

起止页码：103-110

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;EI(收录号：20193807454319);Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：“十二五”国家科技支撑计划课题“木质隔声和发热新材料制造关键技术与示范”(2015BAD14B04)

语种：中文

中文关键词：木质阻尼;多孔材料;填充;小混响室-消声箱法;隔声性能

外文关键词：wood damping;porous material;filled;small reverberation chamber-anechoic chamber method;sound insulation performance

分类号：S781.38

摘要：【目的】利用吸声材料的吸声降噪机制、隔声材料的隔声降噪机制和阻尼材料的阻尼降噪机制,将3种降噪材料以一定形式复合,获得一种兼具吸声、隔声和阻尼性能的新型木质阻尼复合隔声材料,以改善木质材料隔声性能,拓宽木质材料和阻尼材料的应用范围。【方法】先将中密度纤维板(MDF)与橡胶材料在压板温度100 ℃、单位压力3 MPa、加压时间10 min、涂胶量64 g ·m^-2 的工艺条件下进行复合,再利用白乳胶将获得的木质阻尼复合材料与吸声材料粘接,采用小混响室-消声箱法测试复合结构隔声性能,探讨中密度纤维板(MDF)厚度、多孔材料厚度、填充方式、多孔材料种类和阻尼结构等因素对隔声性能的影响。【结果】木质阻尼复合结构中填充聚酯纤维、玻璃纤维和三聚氰胺吸声棉3种不同多孔吸声材料时,在整个频率段,3条隔声性能曲线趋于一致,区别不明显,从减轻复合结构质量及环保角度出发,选择三聚氰胺吸声棉作为填充多孔材料。多孔材料填充方式(BB:利用白乳胶将多孔材料直接粘贴在上下表板上,不含空气层;UU:多孔材料与上下表板不粘接,通过一定厚度空气层分离;BU:多孔材料一侧粘贴在上表板上,另一侧与下表板通过空气层分隔)对复合结构隔声性能具有较大影响,其中BU结构的隔声性能较优。吸声材料与空气层相配合,在不增加复合结构厚度和质量的前提下,可有效提高复合结构的隔声性能,当吸声材料填满空腔时,反而不利于复合结构隔声性能的提高。多孔材料与空气层阻抗不匹配,会增加声波传播途径,声能被损耗。在最佳填充结构的基础上,随着多孔材料厚度从5 mm增加到15 mm,复合结构的隔声性能增加。在低频,共振频率处的隔声性能增加;在临界频率处,多孔材料厚度增加,抑制复合材料的吻合效应,吻合谷变浅,隔声性能增加。MDF厚度增加,复合结构的面密度和刚度增大,可增加复合结构中低频的隔声性能。阻尼结构设计对复合结构隔声性能具有很大影响,自由阻尼结构的耗散能量较小,特别是低频减振效果较差;约束阻尼结构受到振动时,约束层的伸长远远小于黏弹性阻尼层,约束层会阻碍阻尼层的伸长运动;当阻尼层受到压缩时,约束层又会阻碍阻尼层的压缩变形。在阻尼层内除产生拉压变形外,还会产生剪切变形,从而起到比自由阻尼处理更大的耗散振动能作用,阻尼降噪能力更强,可更有效抑制复合结构的共振频率及吻合效应。【结论】表板厚度为6 mm,约束阻尼结构,多孔材料的填充形式为BU结构,填充10 mm三聚氰胺吸声棉和 5 mm 空气层,复合结构的隔声性能较优。
【Objective】 Based on the sound absorption and noise reduction mechanism of sound absorption materials,the sound insulation and noise reduction mechanism of sound insulation materials,and the damping and noise reduction mechanism of damping materials,the three noise reduction materials were compounded in certain forms to obtain a combination of new wood damping composite sound insulation material for sound absorption,sound insulation and damping performance.This research was conducted to improve the sound insulation performance of wood materials,and broaden the application fields of wood materials and damping materials.【Method】 Firstly,MDF and rubber materials were composited under the conditions of hot-pressing temperature of 100 ℃,hot-pressing pressure of 3 MPa,hot-pressing time of 10 min,and a coating amount of 64 g ·m^-2,and a wood damping composite was obtained.The materials were compounded with white latex and a sound-absorbing material.The sound insulation performance was tested using a small reverberation chamber-anchoring chamber method,and the influence of factors such as the thickness of MDF,the thickness of porous material,the filling method,the type of porous material,and the damping structure on its sound insulation performance was investigated.【Result】 When the composite structure was filled with three different porous sound-absorbing materials,those were,polyester fiber,glass fiber,and melamine absorbent cotton,the three sound insulation performance curves tended to be consistent throughout the frequency range.From the viewpoint of reducing the weight and environmental protection of the composite structure,the melamine absorbent cotton was finally determined as a porous material for filling.The filling method of the porous material showed a great influence on the sound insulation performance of the composite structure.The filling method of the porous material were respectively BB,BU and UU.BB is the use of white latex directly to the porous material attached to the upper and lower surface plate,no air layer;UU indicates that the porous material does not bond with the upper and lower surface plates,separated by a certain thickness of the air layer;BU indicates the porous material that one side is affixed to the upper plate,and the other is separated from the lower plate by an air layer.Among the three filling method,the sound insulation performance of the BU structure is superior.When the sound-absorbing material fills the cavity,it is not conducive to the improvement of the sound insulation performance of the composite structure.The sound-absorbing material cooperates with the air layer,and effectively improves the sound insulation performance of the composite structure without increasing the thickness and quality of the composite structure.The impedance of the porous material and the air layer do not match,increasing the propagation path of the acoustic wave,and the acoustic energy is lost.Based on the best filling structure,the influence of the thickness of the porous material on its sound insulation performance was studied.As the thickness increased from 5 mm to 15 mm,the sound insulation performance of the composite structure was improved.At low frequencies,the sound insulation performance at the resonant frequency was increased;at the critical frequency,the thickness of the porous material was increased,inhibiting the anastomosis effect of the composite material,and increasing the shallow sound insulation performance of the anomalous valley.As the MDF thickness increases,the areal density and stiffness of the composite structure increase,improving the low-frequency sound insulation performance of the composite structure.The design of the damping structure had a great influence on the sound insulation performance of the composite structure.The free-dissipation structure has lesd dissipation energy,especially low-frequency vibration damping effect.When the constrained damping structure was subjected to vibration,the elongation of the constraining layer was much smaller than that of the viscoelastic damping layer,so that the constraining layer would hinder the stretching motion of the damping layer.When the damping layer was compressed,the constraining layer hinderd the compression deformation of the damping layer.In addition to tensile and compressive deformation in the damping layer,shear deformation was also produced,which resulted in a greater dissipation of vibration energy than that of free damping.When the damping and noise reduction ability was stronger,the resonance frequency and coincidence effects were more effectively suppressed.【Conclusion】 Based on the analysis of the influence of the above parameters on the sound insulation performance of the composite structure,the material parameters and structure were finally determined.The thickness of the surface plate was 6 mm.The damping structure was confined.The filling form of the porous material was a BU structure,filled with 10 mm melamine absorbent cotton and 5 mm air layer,its sound insulation performance was better.