文献类型：期刊文献

英文题名：Frequency-dependent viscoelastic properties of Chinese fir (Cunninghamia lanceolata) under hygrothermal conditions. Part 1: moisture adsorption

作者：Zhan, Tianyi[1,2] Jiang, Jiali[1] Lu, Jianxiong[1] Zhang, Yaoli[2] Chang, Jianmin[2]

第一作者：Zhan, Tianyi

通信作者：Lu, JX[1]

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, Hunan Collaborat Innovat Ctr Effect Utilizing Woo, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Coll Mat Sci & Engn, Nanjing 210037, Jiangsu, Peoples R China

年份：2019

卷号：73

期号：8

起止页码：727-736

外文期刊名：HOLZFORSCHUNG

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000476623800003)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Funder Id: http://dx.doi.org/10.13039/501100001809, no. 31700487), the Natural Science Foundation of Jiangsu Province (CN) (Funder Id: http://dx.doi.org/10.13039/501100004608, no. BK20170926), the Innovation Fund for Young Scholars of Nanjing Forestry University (CX2017002) and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). Tianyi Zhan would like to gratefully acknowledge the financial support from the Jiangsu Provincial Government Scholarship Program.

语种：英文

外文关键词：adsorption; frequency-dependent; hygrothermal conditions; moisture state; polymer relaxation; time-moisture superposition; viscoelasticity

摘要：To elucidate the frequency-dependent viscoelasticity of wood under a moisture non-equilibrium state, changes in stiffness and damping as a function of frequency were investigated during the moisture adsorption process. The moisture adsorption processes were carried out at six temperatures (30-80 degrees C) and three relative humidity levels (30, 60 and 90% RH). During the moisture adsorption process, the wood stiffness decreased, and damping increased with the increment of moisture content (MC). Regardless of the moisture adsorption time, the wood stiffness increased, and damping decreased with the increasing testing frequency. Based on the re-organized Williams-LandelFerry (WLF) model, the time-moisture superposition (TMS) relation was assumed to be applicable for developing a master curve of wood stiffness during the moisture adsorption process. The frequency ranges of the stiffness master curves spanned from 16 to 23 orders of magnitude at temperatures ranging from 30 to 80 degrees C. however, the TMS relation was not able to predict the wood damping properties during the moisture adsorption process due to the multi-relaxation system of the wood and the nonproportional relationship between free volume and MC at transient moisture conditions.