黏弹性是影响木材加工和利用的关键特性，木材构造各向异性以及所处温湿度场和应力场条件对其黏弹行为具有决定性作用。因此，研究并阐明木材正交异向黏弹性的湿热效应机制，对深入认识木材性质、合理并高效利用木材具有重要价值。然而，目前对木材黏弹性的理解和认识绝大多数是基于单因素/稳态试验条件得出的，鲜有将材料内因（纹理方向、含水率）和环境外因（温湿度、载荷特性）相结合开展系统研究。本项目以人工林杉木为材料，集成应用动态力学分析技术（DMA）、数字图像散斑相关技术（DIC）以及细胞壁组分和结构分析等方法，在系统表征木材正交异向黏弹性的基础上，揭示湿热耦合作用对细胞壁组分和结构的影响规律，从分子水平上阐明木材黏弹性的湿热效应机制，并建立黏弹性本构模型。研究成果可丰富和完善木材流变学的基础理论，为模拟和预测木材在复杂环境中发生的变形与破坏行为规律提供科学依据，对优化木材湿热处理技术具有重要的理论指导意义。

Wood viscoelasticity, which definitively depends on anisotropic structure, temperature-humidity environments and load types, plays an important role in wood utilization and manufacture processes. Therefore, investigating and further clarifying the hydro-thermal coupling mechanisms of wood orthotropic viscoelasticity is of great importance to deeply understand wood properties and utilize wood in an efficient and reasonable way. However, until now, the researches on wood viscoelastic properties are mainly based on the experiments with single factor or steady state, the systematic investigations combining the material factors (grain orientation and moisture content) with environmental factors (temperature-humidity fields and stress fields) are seldom involved. Based on the formerly accumulated research work, the Chinese fir（Cunninghamia lanceolata）plantation wood will be selected as materials in this project. By means of the utilization of dynamic mechanical analysis technique (DMA), digital image correlation method (DIC), cell wall components-structure analysis, etc., this project will systematically characterize the wood orthotropic viscoelastic property, reveal the hydro-thermal effects on the components and structures of wood cell wall, and then give a further explanation for the mechanism of wood viscoelastic behavior response to both heat and moisture content. Finally, the viscoelasticity constitutive model will be derived. The outputs of this project will enrich and improve the theory of wood rheology, provide scientific bases for simulating and forecasting the deformation and fracture behaviors of wood under complex circumstances, and also give theoretical guidance for the improvement and optimization of wood hydro-thermal treatment technology.