摘要
为探究湿心材与对照材物理力学性能差异,以13年生南方型黑杨(XL-90杨)为研究对象,分别测定湿心材与对照材的木材密度、干缩率、湿胀性、抗弯强度、抗弯弹性模量、抗压强度及硬度等物理力学指标,对比分析其物理力学性能差异.结果表明:对照材密度(气干、基本、全干)、干缩率(气干、全干)和湿胀性(气干、饱水)均高于湿心材,且对照材和湿心材的径向干缩率、湿胀性均低于弦向,其中对照材的径向、弦向、体积气干干缩率分别较湿心材提高1.123％、2.335％、3.292％,径向、弦向、体积气干湿胀性分别提高0.916％、3.475％、4.221％.对照材的抗弯强度、抗弯弹性模量、顺纹抗压强度及径向、弦向横纹抗压强度分别较湿心材降低5.617、1 862.853、8.200、0.496、0.426 MPa,湿心材端面、径面、弦面硬度较对照材分别提高613.333、702.917、692.500 N,且对照材与湿心材的抗弯弹性模量、抗压强度、硬度存在显著或极显著差异.XL-90杨湿心材密度、干缩率和湿胀性等物理性能均低于对照材,而抗弯强度、抗弯弹性模量、抗压强度和硬度等力学性能均高于对照材,该研究结果可为XL-90杨在木材加工利用方面提供应用性指导.
Abstract
To explore the differences in physical and mechanical properties between reference wood and wet heartwood of Populus deltoides cl.'Xianglin-90',the 13-year-old P.deltoides cl.'Xianglin-90'were selected as the research objects.The wood density,shrinkage rate,moisture expansion,bending strength,bending elastic modulus,compressive strength and hardness of wet heartwood and reference wood were measured and compared to analyze the differences in their physical and mechanical properties.The results showed that the density(air-dry,basic density,absolutely dried),shrinkage rate(air-dry,absolutely dried)and moisture expansion(air-dry,absolutely wet)were higher than those of the wet heartwood of P.deltoides cl.'Xianglin-90'.Compared to wet heartwood,the radial,tangential,and volumetric air-dried shrinkage rates of reference wood increased by 1.123％,2.335％,and 3.292％,the radial,tangential,and volumetric moisture expansion increased by 0.916％,3.475％and 4.221％,respectively.The bending strength,bending elastic modulus,longitudinal compressive strength,radial transverse compressive strength and tangential transverse compressive strength of reference wood were reduced by 5.617,1 862.853,8.200,0.496,0.426 MPa,respectively,compared to the wet heartwood.The hardness(end,radial,tangential)of wet heartwood respectively increased by 613.333,702.917 and 692.500 N,and there were significant or extremely significant differences in the bending elastic modulus,compressive strength and hardness.The physical properties such as density,shrinkage and moisture expansion of the wet heartwood of P.deltoides cl.'Xianglin-90'were lower than those of the reference wood,and the mechanical properties such as bending strength,bending elastic modulus,compressive strength and hardness were higher than those of the reference wood,the research results can provide applied guidance for the processing process and actual production of P.deltoides cl.'Xianglin-90'in wood.
维普
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