摘要
对不同针、阔叶材树种木材进行吸湿循环处理,通过对声学振动性能进行跟踪测试,研究吸湿循环处理对声学振动性能的改良效果,并探讨木材解剖构造的特异性对其声学振动性能改良效果的影响。以4种常用乐器用材泡桐、梓木、杉木和西加云杉为研究对象,制成标准试样250 mm(纵向)×50 mm(径向)×15 mm(弦向),经60℃干燥48 h后,置于25℃、相对湿度60%的环境中平衡,此为1次循环,共循环4次。测量并计算处理前、不同次数循环处理后4种木材声学振动参数的变化,并结合解剖构造进行分析。木材的纤维/管胞长度从大到小依次为西加云杉>杉木>泡桐>梓木。吸湿循环处理后,4种木材比动弹性模量和声辐射阻尼系数均呈增长趋势,其中泡桐的增长率最大,分别为27.95%和44.37%;西加云杉最小分别为3.84%和7.90%。木材的声阻抗变化率,梓木最大为-15.54%,西加云杉最小为-5.75%。试验结果表明:吸湿循环处理前后,梓木的声学振动性能均为最差;吸湿循环处理改善了木材声学振动性能,阔叶材声学振动性能的改善效果优于针叶材,其中泡桐的改善效果最好;吸湿循环处理2次后,木材比动弹性模量和声辐射阻尼系数、声阻抗均达到稳定,继续2次吸湿循环处理后基本保持不变。
To study the relationship between wood structure and acoustic performance by tracking changes in acoustic vibration performance,the hygroscopic cycle treatments were carried out for different softwood and hardwood species.The influence of wood structure on its acoustic performance improvement effect was discussed.Four common wood species for musical instruments,namely,Paulownia sp.,Catalpa sp.,Cunninghamia lanceolata and Picea sitchenrsis,were used as the research objects.The anatomical properties of these wood species were observed.After drying at low temperature,the standard samples of the four raw materials with a size of 250 mm(L)×50 mm(R)×15 mm(T)were placed in a conditioning chamber at 25℃and 60%relative humidity for the hygroscopic treatment.Four-time cycling was carried out,which took three weeks for each cycle.The changes in the acoustic vibration parameters of the four types of wood were measured and calculated before and after the tests with different cycles.Paulownia sp.and Catalpa sp.are hardwood,and their ratios of vessel were 17.77%and 14.51%,respectively.The wood fibers of Catalpa sp.were shorter than that of Paulownia sp.,those were(836.4±134.4)μm and(1083.7±190.5)μm,respectively.C.lanceolata and P.sitchenrsis are softwood,and P.sitchenrsis cells were longer than C.lanceolata s,being(4354.9±882.1)μm and(3434.0±515.1)μm,respectively.After the hygroscopic cycle treatment,the specific dynamic modulus and sound radiation coefficient of the four kinds of wood showed an increasing trend.Among them,Paulownia sp.had the highest increase rate,with a 27.95%increase in specific dynamic modulus and a 44.37%increase in sound radiation coefficient.The P.sitchenrsis had the smallest increase rate,being 3.84%and 7.90%,respectively.The specific acoustic impedance of Catalpa sp.was the highest(-15.54%),and that of P.sitchenrsis was the lowest(-5.75%).The results showed that:1)C.lanceolata had the best acoustic performance before and after the hygroscopic cycle treatment,and Catalpa sp.was the worst.2)H
作者
余德倩
赵晨鹏
翟胜丞
陈冰炜
阚玉娜
王正
YU Deqian;ZHAO Chenpeng;ZHAI Shengcheng;CHEN Bingwei;KAN Yuna;WANG Zheng(College of Materials Science and Technology,Nanjing Forestry University,Nanjing 210037,China;Co-Innovation Center of Efficient Processing and Utilization of Forest Resources,Nanjing Forestry University,Nanjing 210037,China)
出处
《林业工程学报》
CSCD
北大核心
2021年第5期61-67,共7页
Journal of Forestry Engineering
基金
国家自然科学基金(31400496)
江苏省自然科学基金(BK20140981)。
关键词
吸湿循环处理
木材构造
孔隙
乐器
声学振动性能
hygroscopic cycle treatment
wood structure
pore
musical instruments
acoustic vibration performance
