Longitudinal Mechano-Sorptive Creep Behavior of Chinese Fir in Tension during Moisture Adsorption Processes

Materials

Jinzhen Cao¹  Hui Peng²  Jianxiong Lu²  Jiali Jiang² 

[1] College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China;State Key Laboratory of Tree Genetics and Breeding, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China;

关键词: Chinese fir;    tensile creep;    adsorption;    swelling;    unstable state;   

DOI  :  10.3390/ma10080931

来源: DOAJ

【 摘 要 】

To provide comprehensive data on creep behaviors at relative humidity (RH) isohume conditions and find the basic characteristics of mechano-sorptive (MS) creep (MSC), the tensile creep behaviors, “viscoelastic creep (VEC)” at equilibrium moisture content and MSC during adsorption process, were performed on Chinese fir in the longitudinal direction under 20%, 40%, 60% and 80% RH (25 °C) and at 1, 1.3, and 1.6 MPa, respectively. The free swelling behavior was also measured, where the climate conditions corresponded with MSC tests. Based on the databases of free swelling, VEC, and MSC, the existence of MS effect was examined, and the application of the rheological model under the assumption of partitioned strain was investigated. The results revealed that both VEC and MSC increased with magnitude of applied stress, and the increasing RH level. Under all RH isohume conditions, the total strain of MSC was greater than that of VEC. The influence of RH level on VEC was attributed to the water plasticization effect, whereas that on MSC was presumed to be the effect of water plasticization and unstable state in the wood cell wall. In addition, the RH level promoted the relaxation behavior in MSC, while it slightly affected the relaxation behavior in VEC. In the future, the rheological model could consider the link between load configuration and the anatomic structural feature of wood.

【 授权许可】

Unknown