文献类型：期刊文献

英文题名：Orthotropic Viscoelastic Properties of Chinese Fir Wood Saturated with Water in Frozen and Non-frozen States

作者：Li, Zhu[1,2] Jiang, Jiali[1] Lyu, Jianxiong[1] Cao, Jinzhen[2]

第一作者：李珠;Li, Zhu

通信作者：Lyu, JX[1]

机构：[1]Chinese Acad Forestry, Hunan Collaborat Innovat Ctr Effect Utilizing Woo, Res Inst Wood Ind, Beijing, Peoples R China;[2]Beijing Forestry Univ, Coll Mat Sci & Technol, Beijing, Peoples R China

年份：2021

卷号：71

期号：1

起止页码：77-83

外文期刊名：FOREST PRODUCTS JOURNAL

收录：;EI(收录号：20212110377473);Scopus(收录号：2-s2.0-85104983746);WOS:【SCI-EXPANDED(收录号:WOS:000665397800010)】；

基金：This research was financially supported by the National Natural Science Foundation of China (No. 31971591).

语种：英文

外文关键词：Forestry - Plants (botany)

摘要：In order to better understand the differences in orthotropic viscoelastic properties of Chinese fir (Cunninghamia lanceolata) in frozen and non-frozen states, the storage modulus (E') and loss modulus (E '') of the longitudinal, radial, and tangential specimens were investigated under water-saturated conditions with temperatures ranging from -120 degrees C (or 30 degrees C) to 280 degrees C. Results revealed that the order of magnitude in E' for each orientation was consistent for temperatures below 0 degrees C, while the anisotropy in E' was reduced due to the enhancement effect of ice. Frequency-dependent c-relaxation was observed at approximately -96 degrees C for all orthotropic directions. A sharp discontinuity in E' occurred at approximately 0 degrees C for each specimen, together with the corresponding sharp peak in the E '' spectrum. Furthermore, the frozen free water had an effect on the orthotropic viscoelastic behavior in the water-saturated specimens within the range of -120 degrees C to 280 degrees C. Specimens with a frozen history leveled off at the initial temperature ramping phase for each orientation, while a frozen history reduced the decline in stiffness of the wood specimens. Similar to the variations in E', the dramatic loss of water increased the complexity of the E '' values. The loss of free water also had a pronounced effect on the viscoelastic properties during the temperature ramping process. Thus, in the wood industry, it necessary to consider the variations in the orthotropic viscoelastic performance of specimens under water-saturated conditions during the water loss process.