| 摘要: |
| 【目的】分析四川产蓝桉幼龄材的物理力学性质及密度变异规律,为提高其利用效率、扩展其利用方式提供参考。【方法】参照木材物理力学性质测试国家标准,对5年生蓝桉的物理力学性质(气干径向干缩率、弦向干缩率、体积干缩率,全干径向干缩率、弦向干缩率、体积干缩率,气干密度、绝干密度和基本密度,顺纹抗压强度、抗弯强度、抗弯弹性模量、顺纹抗剪强度和端面、径面和弦面硬度等)进行了测定,并分析了其木材密度变异特性。【结果】5年幼龄四川蓝桉用材的气干径向、弦向、体积干缩率分别为2.38%,4.01%,6.75%;全干径向、弦向、体积干缩率分别为3.71%,5.65%,9.14%;气干密度、全干密度和基本密度分别为0.46,0.41,0.38 g/cm3,3种密度在径向上均呈现出先减小后增大的变异规律,而在在轴向上,从基部到2 m处基本保持不变,到4 m处下降到最小,且下降幅度较大,4 m以上随着树高的增加而增加;木材顺纹抗压强度为24.80 MPa,抗弯强度为58.26 MPa,抗弯弹性模量为6 444.24 MPa,顺纹抗剪强度为2.31 MPa,端面、径面和弦面硬度平均值分别为3.10,2.20,1.96 kN。四川蓝桉5年幼龄材的综合强度为83.06 MPa,综合强度较小。【结论】蓝桉幼龄材物理力学性质较小,密度变异规律显著。 |
| 关键词: 蓝桉 幼龄材 物理性质 力学性质 密度变异 四川 |
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| 基金项目:四川省高等学校重点实验室项目“木材工业与家具工程” |
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| Physical-mechanical properties of Eucalyptus globulus juvenile wood from Sichuan |
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LUO Hao,QI Jin-qiu,XIE Jiu-long,et al
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| Abstract: |
| 【Objective】This study analyzed physical and mechanical properties and variation in density of Eucalyptus globulus from Sichuan to provide reference for improving efficiency and expanding use patterns.【Method】The physical-mechanical properties (radial air-dried shrinkage,tangential air dried shrinkage,volume air-dried shrinkage,radial over-dried shrinkage ratio,tangential over-dried shrinkage ratio,volume over-dried shrinkage ratio,air-dried density,dried density,basic density,compressive strength parallel to grain,bend elastic modulus,compressive strength,shear strength parallel to grain,end section hardness,radial section hardness,and tangential section hardness) of 5-year-old Eucalyptus globulus were tested based on National Standards and the variation in density was analyzed.【Result】 The air-dried shrinkages of radial,tangential and volume were 2.38%,4.01%,and 6.75%.The over-dried shrinkages were 3.71%,5.65%,and 9.14%,respectively.The air-dried density,dried density and basic density were 0.46,0.41,and 0.38 g/cm3 and all three densities showed similar variation of first decrease followed by increase from pith to bark.In the axial direction,they were unchanged from the base to 2 m and dropped to the smallest at 4 m height before increasing as the increase of stem height above 4 m.The compressive strength parallel to grain was 24.80 MPa,the bending strength was 58.26 MPa,the bending elastic modulus was 6 444.24 MPa,and the shear strength parallel to grain was 2.31 MPa.The hardnesses in end,radial and tangential sections were 3.10 kN,2.20 kN,and 1.96 kN,respectively.The composite strength of Sichuan 5-year-old Eucalyptus globulus was 83.06 MPa,belonging to low level.【Conclusion】Eucalyptus globulus juvenile wood had low physical and mechanical properties and significant density variation. |
| Key words: Eucalyptus globulus juvenile wood physical properties mechanical properties density variation Sichuan |