Chen Xudong, Cheng Yingyao, Chan Andrew, Holloway Damien, Nolan Gregory
School of Civil Engineering, Suzhou University of Science and Technology, Suzhou 215011, China.
School of Engineering, College of Sciences and Engineering, University of Tasmania, Hobart, TAS 7001, Australia.
Polymers (Basel). 2022 Jun 13;14(12):2390. doi: 10.3390/polym14122390.
Plantation-grown Eucalyptus nitens (E. nitens) has been grown predominantly for the pulp and paper industry. In this study, the suitability of E. nitens as a structural material is examined using static tensile tests in a universal testing machine. The anisotropic tensile behaviour of 240 Eucalyptus nitens small clear wood samples with a diversity of grain angles was examined in both dry and wet conditions. The samples had a highly anisotropic tensile characterisation in the context of both a low moisture content (MC = 12%) and a high moisture content (MC > its fibre saturation point, FSP). The results showed that, in a high moisture content condition, the wood showed a lower failure strength and more ductility at all grain angles than in a low moisture content condition. The underlying failure mechanism of Eucalyptusnitens timber in tension was determined in detail from the perspective of the microstructure of wood cellulose polymer composites. The mean tensile failure strengths perpendicular and parallel to the fibre direction were, respectively, 5.6 and 91.6 MPa for the low MC and 3.8 and 62.1 MPa for the high MC condition. This research provides a basis for using E. nitens as a potential structural tensile member. The moisture modification factors of Eucalyptus timber at a mean level are higher than those of the traditional construction material, Pinus radiata, implying that E. nitens is promising as a material to be used for tensile members in water saturated conditions.
人工种植的尼氏桉（E. nitens）主要用于制浆造纸工业。在本研究中，使用万能材料试验机进行静态拉伸试验，检验了尼氏桉作为结构材料的适用性。研究了240个具有不同纹理角度的尼氏桉小规格无缺陷木材样本在干燥和潮湿条件下的各向异性拉伸行为。在低含水率（MC = 12%）和高含水率（MC > 其纤维饱和点，FSP）情况下，样本均具有高度各向异性的拉伸特性。结果表明，在高含水率条件下，与低含水率条件相比，木材在所有纹理角度下的破坏强度更低，延展性更强。从木材纤维素聚合物复合材料微观结构的角度详细确定了尼氏桉木材拉伸时的潜在破坏机制。低含水率条件下，垂直和平行于纤维方向的平均拉伸破坏强度分别为5.6 MPa和91.6 MPa，高含水率条件下分别为3.8 MPa和62.1 MPa。本研究为将尼氏桉用作潜在的结构拉伸构件提供了依据。尼氏桉木材的平均含水率修正系数高于传统建筑材料辐射松，这意味着尼氏桉有望作为在水饱和条件下用于拉伸构件的材料。
