宣纸的力学行为研究

The Research on Mechanical Behavior of Xuan Paper

以宣纸为研究对象,对它在拉伸过程中产生的应力-应变特性进行详细研究。结果表明:断裂应力随着拉伸速度的增加而增加,但拉伸速度对断裂应变没有明显的趋向性影响;不同品种的宣纸应力—应变曲线不同,含长纤维多的特种净皮断裂应力和应变最大,棉料的断裂应力和应变最小;宣纸横向的断裂应力和应变比纵向的大,在相同的应力下,横向的应变小于纵向;宣纸的含水率影响纸的弹性和可塑性,随着水分增加,弹性逐渐降低,可塑性逐渐增加,断裂应力随着水分的增加而下降;宣纸具有粘弹性的特点,在拉伸作用下发生的形变包括弹性形变、粘弹性形变和塑性形变。

Xuan paper was selected as materials in the paper. Character of stress-strain of Xuan paper during the stretching process was studied. Results are as follows： The breaking stress was increased as the speed of stretch. However, the speed cannot serve any conspicuous effect on the direction of tendency of breaking strain.Different kinds of Xuan paper had different stress-strain curves. Super bark including much more longer fibers had the greatest breaking stress and strain. The breaking stress and strain of cotton stock were the smallest.The stress-strain curves of Xuan paper were different between longitudinal and cross direction, and the breaking stress and strain were greater in cross direction than in longitudinal one. Under the same stress load, cross strain was less than longitudinal one. Moisture of Xuan paper influenced the elasticity and plasticity of paper. When the water content increased, the elasticity was decreased, the plasticity was enhanced and the breaking stress was gradually declined accordingly. Xuan paper had viscoelastic characteristics. The deformation of stretching included elastic ,viscoelastic and plastic deformation.