黑沙蒿单根变形特性研究

为探究轴向、径向荷载下植物根系对弹性变形的适应与抵抗特性,以水土流失地区常见植物种黑沙蒿根系为对象,采用TY8000伺服控制试验机,研究1～5 mm径级范围内黑沙蒿直根及含侧根分支处根段承受轴向、径向荷载下弹性模量与刚度的变化。结果表明:直根及含侧根分支处根段力-位移曲线(F-s曲线)承受轴向荷载时呈上凸形,承受径向荷载时呈下凹形;直根段、含侧根分支处根段的拉伸弹性模量、弯曲弹性模量均与根径幂函数负相关,抗拉刚度及抗弯刚度与根径幂函数正相关;弹性模量与刚度在轴向荷载下表现出较大的差异,在径向荷载下差异不显著。试验结果说明黑沙蒿较细根适应变形能力更强,较粗根抵抗变形能力更强,且根型影响变形性质。

Deformation Characteristics of Single Root of Artemisia ordosica Species

To clarify the adaptation and resistance of the roots of Artemisia ordosica to elastic deformation under axial or radial loads, the elastic modulus and stiffness of the straight roots and lateral roots of the plants with diameters from 1-5 mm were measured with TY8000 servo control testing machine. The results showed that the force-displacement curve (F-s curve) was convex under the axial load; the F-s curve was concave under the radial load; the tensile modulus and the bending modulus were negatively correlated with power function of the root diameter; the tensile stiffness and the bending stiffness were positively correlated with power function of the root diameter; the elastic modulus and stiffness of the two types of roots presented a significant difference under axial load, and no significant difference under radial load.Overall,the roots of Artemisia ordosica which can adapt to deformation and the larger roots are more resistant to deformation than the small roots; the root types canaffect deformation characteristics.