文献类型：期刊文献

英文题名：Effect of thermal expansion at low temperature on mechanical properties of Birch wood

作者：Zhao, Liyuan[1] Jiang, Jinghui[1] Lu, Jianxiong[1]

第一作者：Zhao, Liyuan

通信作者：Lu, JX[1]

机构：[1]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Res Inst Wood Ind, Beijing 100091, Peoples R China

年份：2016

卷号：126

起止页码：61-65

外文期刊名：COLD REGIONS SCIENCE AND TECHNOLOGY

收录：;EI(收录号：20161502228498);Scopus(收录号：2-s2.0-84962676474);WOS:【SCI-EXPANDED(收录号:WOS:000374992400009)】；

基金：The authors would like to acknowledge the financial support from a grant of Research Institute for New Forestry Technology of Chinese Academy of Forestry (CAFINT2013C09).

语种：英文

外文关键词：Low temperature; Thermal expansion; Mechanical properties; Crystallinity

摘要：Thermal expansion phenomenon would occur in woody materials in terms of temperature change as well as moisture content (MC), which will influence the mechanical properties in extreme low temperature condition. In this study, thermal expansion of birch (Betula platyphylla) wood with three levels of MC (water-saturated specimen with a MC of 149.7%, air-dried one with a MC of 9.7% and oven-dried one with a theoretical MC of 0%), was analyzed for temperature ranging from -150 to + 20 degrees C. Furthermore, the dimension changes of the birch specimens were measured and the effect of thermal expansion on the mechanical properties in low temperature condition was investigated. The crystallinity of the wood at low temperatures was examined by the X-ray diffraction (XRD). The results showed that all specimens shrank from + 20 to -150 degrees C. Water-saturated wood showed more dramatic shrinkage as compared to the other two groups (air/oven-dried). The value of the linear thermal expansion coefficient. increased with the increasing temperature. At any temperature,. of the water-saturated specimen was the greatest one among the three groups. The increase of MOR, i.e., the variation between the corrected MOR adjusted according to the. at low temperature and the uncorrected one, had a linear relationship with temperature, which would provide a method for the forecast of actual MOR at low temperature according to the value at room temperature. XRD analysis indicated that the crystalline structure of wood polymers was not influenced by temperature. Stability and mechanical property offer insight of the performance of wood product used for low temperature applications. (C) 2016 Elsevier B.V. All rights reserved.