樟子松木材横纹压缩时黏弹性与能量吸收特性研究

以樟子松为研究对象,利用横纹压缩蠕变试验研究其木材吸能特性与黏弹性的关系。结果表明:樟子松木材在静态横纹压缩径向加载时,存在明显三段式曲线,第2阶段平台区体现了良好的能量吸收特性; 樟子松木材横纹压缩时的短期蠕变行为可用四元件流变模型进行描述; 随着应力水平的上升,樟子松木材的瞬间弹性模量和Kelvin模型中的延时弹性模量及黏性系数均呈上升趋势,而Maxwell模型中的黏性系数和松弛时间呈明显下降趋势; 在蠕变时,随着应力水平的上升,樟子松木材的能量吸收能力增加且缓冲系数呈下降趋势。

Viscoelastic and energy absorption characteristics of scotch pine wood in across-compression

This paper investigated the relationship between viscoelasticity and energy absorption characteristics of scotch pine wood by across-compression creep tests. The results showed that the stress-strain curve occupied three typical regions when scotch pine was across compressed with load in radial direction. The second region in the stree-strain curve, a plateau, embodied good characteristics of energy absorption. A four-elements model could be used to study the creep performance of scotch pine in short term. When the stress increased, the instantaneous elastic modulus, delayed elastic modulus and glutinous coefficient of the Kelvin model all increased. On the contrary, the glutinous coefficient of the Maxwell model and relaxation time decreased with increasing stress level. In creep test, when the stress levels increased, the energy absorption ability of scotch pine increased correspondingly, but the cushioning coefficient decreased.