不同树龄尾巨桉无性系木材物理与力学性能评价  

Evaluation of Wood Physical and Mechanical Properties in Eucalyptus urophylla×E.grandis Clone Plantations at Different Ages

作　　者：黄腾华[1] 王军锋[1] 栾洁[1] 宋恋环 雷福娟[1] HUANG Tenghua;WANG Junfeng;LUAN Jie;SONG Lianhuan;LEI Fujuan(Guangxi Zhuang Autonomous Region Forestry Research Institute/Guangxi Quality Control of Wood Resources Cultivation Research Center of Engineering Technology,Nanning,Guangxi 530002,China)

机构地区：[1]广西壮族自治区林业科学研究院/广西木材资源培育质量控制工程技术研究中心,广西南宁530002

出　　处：《热带农业科学》2021年第5期95-100,共6页Chinese Journal of Tropical Agriculture

基　　金：广西林科院基本科研业务费项目(No.林科201826号)。

摘　　要：为了解不同树龄尾巨桉无性系木材物理力学性能,以5年和7年生尾巨桉无性系木材为对象,按照国家标准对其基本密度、气干密度、全干密度、干缩特性、硬度、顺纹抗压强度、抗弯强度、抗弯弹性模量和冲击韧性等物理力学指标进行系统测试和分析。结果表明:5年生尾巨桉木材基本密度、气干密度、全干密度分别为0.424、0.533和0.498 g/cm3,基本密度和气干密度均为2级;气干和全干差异干缩分别为2.78、2.28,分别达到5级、4级;弦向、径向和体积干缩系数平均值分别为0.297%、0.154%、0.474%,体积干缩系数达到3级,尺寸稳定性较差;7年生尾巨桉木材基本密度、气干密度、全干密度分别为0.438、0.543和0.507 g/cm3,基本密度和气干密度均为2级;气干和全干差异干缩分别为2.35、2.07,分别达到4级、3级;弦向、径向和体积干缩系数平均值分别为0.254%、0.157%、0.425%,体积干缩系数达到3级,尺寸稳定性较差;5年生和7年生尾巨桉木材的顺纹抗压强度分别为44.8、46.3 MPa,均为2级;抗弯强度分别为80.3、83.8 MPa,均为2级;抗弯弹性模量分别为10032、10805 MPa,均为2级;冲击韧性分别为44.2、46.6 kJ/m^(2),均为2级;端面硬度分别为4158、4494 N,均为3级;弦面硬度分别为3175、3388 N,均为3级;径面硬度分别为2759和2951 N,属于中等硬度木材;综合品质系数分别为29.5×10^(7) Pa、29.7×10^(7 )Pa,为高等级材。研究结果为尾巨桉定向培育及其木材加工利用提供参考。Wood samples of Eucalyptus urophlla×E.grandis clone were collected from the plantations at the ages of 5 years and 7 years to analyze their differences in physical and mechanical properties.The physical and mechanical indexes such as basic density,air-dry density,oven-dry density,dry shrinkage characteristics,hardness,compressive strength parallel to grain,bending strength,modulus of elasticity,and toughness were systematically determined and analyzed according to the Chinese national standards.For the wood samples of the 5-year-old E.urophylla×E.grandis clone the basic density,air-dry density and oven-dry density were 0.424 g/cm3,0.533g/cm3 and 0.498g/cm3,respectively,and the basic density and air-dry density belonged to grade 2;the differential shrinkage was 2.78 for air dried wood and 2.28 for oven-dried wood,and both wood samples belonged to grades 5 and 4;the tangential,radial and volume shrinkage coefficients averaged 0.297%,0.154%and 0.474%,respectively,and the volume shrinkage coefficient belonged to grade 3,indicating poor dimensional stability.For the wood samples of the 7-year-old E.urophylla×E.grandis clone the basic density,air dry density and oven-dry density were 0.438%,0.543%and 0.507%,respectively,and the basic density and air-dry density belonged to grade 2;the differential shrinkage was 2.35 for air dried wood and 2.07 for oven-dried wood,and both wood samples belonged to grades 4 and 3;the average tangential,radial and volume shrinkage coefficients were 0.254%,0.157%and 0.425%,respectively,and the volume shrinkage coefficient belonged to grade 3,indicating poor dimensional stability.For the wood samples of the 5-year-old and 7-year-old E.urophylla×E.grandis clones the compressive strength parallel to grain was 44.8 MPa and 46.3MPa,respectively,both belonging to grade 2;the bending strength was 80.3 MPa and 83.8MPa,respectively,both belonging to grade 2;the moduli of elasticity were 10032 MPa and 10805 MPa,respectively,both belonging to grade 2;the toughness of wood was 44.2 kJ/m2 and 46.6

关 键 词：尾巨桉 无性系 木材 物理力学性能 

分 类 号：S781.2[农业科学—木材科学与技术]