重组竹方销对正交胶合木力学与声学特性的影响  

The influence of bamboo scrimber cotters on sound insulation and mechanical properties of cross-laminated timber

作　　者：吴玥 王雨桐 黄紫蓝 林杨帆[2] 李宏敏 王志强 朱一辛 WU Yue;WANG Yutong;HUANG Zilan;LIN Yangfan;LI Hongmin;WANG Zhiqiang;ZHU Yixin(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;College of Science,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037 [2]南京林业大学理学院,南京210037

出　　处：《林业工程学报》2024年第2期152-159,共8页Journal of Forestry Engineering

基　　金：国家重点研发计划(2021YFD2200605)。

摘　　要：为提升正交胶合木(CLT)的中低频隔声性能,设计了一种以重组竹方销为声散射体的二维声子晶体结构的CLT,探究对嵌入重组竹方销的杉木CLT力学和声学特性的影响。采用短梁剪切法,研究了跨中面外开孔的CLT短梁和嵌入重组竹方销的CLT短梁层间剪切强度、最大正应力和静态韧性系数;采用阻抗管测试法,研究了周期性排布的重组竹方销对CLT隔声量的影响规律。短梁剪切试验表明:与未开孔CLT相比,开孔使CLT的层间剪切强度下降了13.0%~16.5%;与开孔CLT相比,方孔中嵌入重组竹方销可使开孔CLT的层间剪切强度提升8.5%~12.7%,从而与未开孔CLT的层间剪切强度差异不显著,其最大正应力分别与开孔和未开孔的CLT最大正应力差异不显著,为24.52~29.45 MPa;方孔中嵌入重组竹方销的CLT在静态韧性系数上相比未开孔的CLT上升了13.9%~19.1%。隔声量测试结果表明:嵌入重组竹方销的CLT属局域共振型声子晶体结构,在1 400 Hz出现吻合效应的隔声量谷值约33.41 dB;以重组竹方销为声散射体的二维声子晶体结构随重组竹方销边长的增加,提高了CLT的密度和中低频的隔声量,其中,600 Hz以下的隔声量可提升约20.22%。在不改变CLT厚度、密度增量小于20%且力学性能差异不显著的前提下,以重组竹方销增强CLT隔声性能是可行的。Sound insulation is to minimize the sound transmission from one room to another,which is an important property for building materials.In order to improve the low and medium frequency sound insulation performance of cross-laminated timber(CLT),a two-dimensional phononic crystal structured CLT with bamboo scrimber square cotters as the acoustic scatterers was designed to investigate the mechanical and sound insulation properties of CLT embedded with bamboo scrimber square cotters.The interlaminar shear strength,maximum positive stress,and static toughness coefficient of CLT short-beams with holes outside the mid-span face and those embedded with bamboo scrimber square cotters were investigated by the short-beam shear method.The influence of periodically arranged bamboo scrimber square cotters on the sound insulation of CLT was studied by the impedance tube test method.The short-beam shear test showed that the square holes in the CLT reduced the interlaminar shear strength by 13.0%-16.5%.The embedding of the bamboo scrimber square cotters in the square holes increased the interlaminar shear strength of the CLT with square holes by 8.5%-12.7%,which resulted in a non-significant difference in the interlaminar shear strength between the CLTs with and without holes.The differences of maximal positive stress between the CLT with and without square holes were in the range of 24.52-29.45 MPa.The CLT with bamboo scrimber square cotters embedded in the square holes showed an increase in static toughness coefficients of 13.9%-19.1%compared to the CLT without holes.The sound insulation test results showed that the CLT embedded in bamboo scrimber square cotters was a local resonance phononic crystal structure.Single bamboo scrimber square cotters were spaced 25 mm apart at the top,bottom,left and right,and set in arrays in the CLT.The valley value of the sound reduction index with the anastomosis effect at 1400 Hz was about 33.41 dB.Between 100 and 400 Hz,the sound insulation curve of the CLT embedded in bamboo scrimber square

关 键 词：声子晶体 重组竹方销 正交胶合木 层间剪切强度 静态韧性系数 

分 类 号：S781.9[农业科学—木材科学与技术]