摘要
为揭示杉木无性系与实生苗木材物理力学性能的差异,以26年生杉木无性系和实生苗人工林木材为研究对象,对其不同圆周方位(南北向)、不同高度位置的主要物理力学性能进行测定,考察木材强度品质系数,综合评定杉木无性系和实生苗木材的材质等级.结果表明:除冲击韧性外,杉木无性系木材的密度、干缩率、差异干缩、湿胀率(全干-气干)、硬度、抗弯强度、抗弯弹性模量、顺纹抗压强度和横纹抗压强度均高于实生苗木材;圆周方位对杉木无性系与实生苗木材物理力学强度影响不显著;树高对杉木无性系木材气干密度、吸水率,实生苗木材基本密度、气干密度、吸水率、横纹抗压强度、硬度影响极显著,对无性系木材基本密度、全干密度、体积湿胀率,实生苗木材全干密度、体积湿胀率影响显著,对2种木材其他物理力学强度影响不显著;2种木材的气干密度、端面硬度、横纹抗压强度和顺纹抗压强度随树高增加呈现先降低后升高的趋势;除干缩性外,2种木材各物理力学性质指标均在国产材中属低等级;2种杉木木材综合品质系数较高,均为高等级材.
Abstract
In order to reveal the differences in the physical and mechanical properties of wood from Cunning-hamia lanceolata clones and seedling plantations,the main physical and mechanical properties of wood from 26-year-old C.lanceolata clones and seedling plantations at different circumferential orientations(north-south orient-ation)and different height positions were measured,and the wood strength and quality coefficients were investig-ated to comprehensively evaluate the material grades of wood from C.lanceolata clones and seedling plantations.The results showed that in addition to impact toughness,the density,shrinkage,difference shrinkage,swelling rate(all dry-air dry),hardness,flexural strength,flexural modulus of elasticity,compressive strength parallel to grain,and transverse compressive strength of C.lanceolata clones were higher than those of seedlings;the influ-ence of circumferential orientation on the physical and mechanical strength of C.lanceolata clones and seedlings was not significant;tree height had a significant impact on the air dry density and water absorption of C.lanceol-ata clones wood,the basic density,air dry density,water absorption,transverse compressive strength,and hard-ness of seedling wood,while it had a significant impact on the basic density,total dry density,and volume mois-ture expansion of clone wood,the total dry density,and volume moisture expansion of seedling wood,and had no significant impact on other physical and mechanical strength of the 2 types of wood;the air dried density,end hardness,transverse compressive strength,and longitudinal compressive strength of the 2 types of wood showed a trend of first decreasing and then increasing with the increase of tree height;in addition to the shrinkage,the phys-ical and mechanical properties of the 2 types of wood were in the low-grade of domestic wood;the comprehens-ive quality coefficient of the 2 types of C.lanceolata wood was relatively high,and they were both high-grade wood.
国家科技期刊平台
NSTL
万方数据