摘要
【目的】探究抽提处理对乐器用泡桐木材声学振动性能的影响,为木材声学品质改良提供理论依据,促进我国乐器产品声学品质提高,缓解乐器共鸣板用优质木材资源日益匮乏的局面。【方法】采用苯甲醇、去离子水、二氯甲烷和无水乙醇4种溶剂对泡桐木材进行15天的抽提处理,基于两端自由的弯曲振动方法,测定并分析抽提处理对木材弹性模量E、剪切模量G、比动弹性模量E/ρ、对数衰减系数σ、声阻抗ω、声辐射品质常数R、E/G、传声速度υ、传输参数υ/σ、声转换效率υ/(σ·ρ)等声学振动性能参数的影响规律,并通过微观结构观察、红外光谱(FTIR)和X射线衍射(XRD)的变化,分析抽提处理对木材声学振动性能的影响机理。【结果】经去离子水、二氯甲烷、苯甲醇和无水乙醇抽提处理后,泡桐木材声学振动性能参数均发生变化。比动弹性模量E/ρ、声辐射品质常数R和传声速度υ平均增加7.67%、11.36%和3.75%,其中经二氯甲烷抽提处理的改善效果最佳,增幅分别为13.99%和17.28%和6.77%;声阻抗ω和对数衰减系数σ平均降低3.23%和19.42%,经去离子水抽提处理后其下降程度最大,降幅分别为-5.03%和-23.45%。从能量利用率来看,声转换效率υ/(σ·ρ)和传输参数υ/σ平均提高38.89%和29.21%,其中经二氯甲烷抽提处理的改善效果最佳,增幅分别为47.66%和35.10%。抽提处理后泡桐木材红外光谱曲线未发生明显变化,仅羟基和半纤维素的吸收峰强度细微减弱。从木材微观结构看出,抽提处理后导管和纹孔更加清晰,并保留木材多孔性能。XRD分析表明,抽提处理未改变衍射峰位置,仅影响衍射峰强度,苯甲醇、去离子水、二氯甲烷和无水乙醇抽提处理后泡桐木材相对结晶度分别增加4.73%、10.25%、3.56%和7.66%,其中经二氯甲烷抽提处理的变化率最大,增大比率为17.42%。【结论】抽提处理可改善泡桐木材声学振
【Objective】This study was carried out to explore the influences of extraction treatments on the acoustic vibration performance of paulownia wood used for Chinese national musical instrument,with the aims to provide a theoretical basis for the improvement of wood acoustic quality,promote the improvement of acoustic quality of Chinese musical instrument products,and alleviate the increasingly scarce situation of high-quality wood resources for musical instrument soundboards.【Method】Four solvents(benzyl alcohol,deionized water,dichloromethane and absolute ethanol)were used to extract paulownia wood for 15 days.Based on the free bending vibration method,the effects of extraction treatments on the acoustic vibration performance parameters such as elastic modulus E,shear modulus G,specific dynamic elastic modulus E/ρ,logarithmic attenuation coefficientσ,acoustic impedanceω,acoustic radiation quality constant R,E/G,sound transmission speedυ,transmission parameterυ/σand acoustic conversion efficiencyυ/(σ·ρ)were measured and analyzed.The influence mechanisms of extraction treatments on acoustic vibration performances were analyzed by microstructure observation,infrared spectroscopy(FTIR)and X-ray diffraction(XRD).【Result】Acoustic performance parameters of paulownia wood were changed after extracting by deionized water,dichloromethane,benzyl alcohol and absolute ethanol.The specific dynamic elastic modulus E/ρ,acoustic radiation quality constant R and sound transmission speedυincreased by 7.67%,11.36%and 3.75%,respectively.The improvement effect of dichloromethane extraction treatment was the best,with an increase of 13.99%,17.28%and 6.77%,respectively.The acoustic impedanceωand logarithmic attenuation coefficientσdecreased by 3.23%and 19.42%,on average.The maximum decrease was-5.03%and-23.45%,respectively,after deionized water extraction.From the perspective of energy utilization,the acoustic conversion efficiencyυ/(σ·ρ)and transmission parameterυ/σincrease by 38.89%and 29.21%,on average.Th
作者
李瑞
苗媛媛
钱晓东
林斌
金祥龙
李慕之
刘镇波
Li Rui;Miao Yuanyuan;Qian Xiaodong;Lin Bin;Jin Xianglong;Li Muzhi;Liu Zhenbo(Key Laboratory of Bio-Based Material Science and Technology of Ministry of Education, Northeast Forestry University ,Harbin 150040;Engineering Research Center of Advanced Wooden Materials, Ministry of Education ,Harbin 150040)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2022年第2期171-181,共11页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(31670559)
中央高校基本科研业务费专项资金项目(2572019BB05)。
关键词
抽提处理
泡桐
声学振动性能
extraction treatment
paulownia
acoustical vibration characteristics
