木材干燥应力数学模型

用切片法对木荷的干燥应力进行测试。用回归分析和聚类分析建立了干燥应力的数学模型。通过分析得出；木材弹性模量在干燥过程中不是常数，随含水率下降而增加；木材弹性应力和残余应力在厚度方向上的分布分别近似为四次多项式和二次多项式。应力的极值点发生在木材的表层和中心层，含水率应力与含水率之间近似为线性或二次多项式关系；木材干燥应力变化过程可分类三个阶段。

The Mathematics Models of Wood-drying Stress

The wood-drying stress of Schima superba was measured by section, and the mathematics models of wood-drying stress were set up through the regression and the cluster analysis The conclusions show that the wood-drying elastic modulus are not constant, and increase with the moisture content decrea-sing The distributions of wood-drying elastic stress and residual stress are quartic and quadratic polynomial respectively The maximum of stress are on the surface and in the middle of the lumber The varied procedure of drying stress can be devided into three stages