含水率对木材细胞壁黏弹性性能影响研究

Study on the Influence of Water Content on the Viscoelastic Properties of Wood Cell Wall

采用纳米压痕静态和动态分析技术,研究了不同含水率马尾松木材的蠕变性能及动态黏弹性。首先在不同环境条件下调节样品含水率,分别为绝干、5.8%、11.2%和20.1%,然后利用纳米压痕技术测试木材的蠕变性能,并利用伯格斯模型,研究木材细胞壁静态黏弹性性能对水分的依赖关系。根据试验结果计算蠕变柔量,在含水率为20.1%、11.2%、5.8%和绝干时,其保载阶段最后蠕变柔量分别为0.638、0.472、0.387 GPa;和0.325 GPa;。最后,利用纳米压痕动态分析技术,获得木材细胞壁动态黏弹性性能。结果表明:随着含水率降低,细胞壁储存模量逐渐增加,而损耗模量逐渐下降。

The creep properties and dynamic viscoelasticity of masson pine wood with different moisture content were studied by using static and dynamic analysis techniques of nano indentation. Firstly, the moisture content of samples was adjusted to oven dry, 5.8%, 11.2% and 20.1% under different environmental conditions,respectively. Then, the creep properties of wood were tested by nano-indentation technology, and the dependence of static viscoelastic properties of wood cell wall on moisture was studied by using Burgess model. The creep compliance was calculated according to the test results. When the water content was 20.1%, 11.2%, 5.8% and dry out, the final creep compliance was 0.638、0.472、0.387 GPa;and 0.325 GPa;respectively in the loading stage. Finally, the dynamic viscoelastic properties of wood cell wall were obtained by nano-indentation dynamic analysis technique. The results showed that with the decrease of water content, the cell wall storage modulus increases and the loss modulus decreases.