6种防风植物枝条生物力学特性及影响因素

Branches Tensile Mechanical Characteristics and the Influencing Factors of Six Plant Species in Inner Mongolia

为了揭示植物地上部分枝条防风抗蚀生物力学响应机制、筛选合适的防风树种,以内蒙古准格尔露天煤矿排土场6种常见植物枝条为对象,进行室内瞬时极限拉伸试验,研究枝条极限抗拉强度以及不同加载速度、枝径和枝条水分变化对极限抗拉强度的影响及其变化规律。结果表明：测试植物枝径0~3mm范围枝条平均极限抗拉强度随加载速度的增加而增加、随直径增加呈降低趋势,极限抗拉强度大小顺序为柠条（50.13 MPa）〉沙棘（37.27MPa）〉紫花苜蓿（30.25MPa）〉沙打旺（22.74MPa）〉草木樨（22.22MPa）;枝条水分变化对其极限抗拉强度的影响表现为枝条越细,对水分变化的敏感程度也越高,继而对极限抗拉强度的影响越大,即直径相同情况下水分损失率越大则平均极限抗拉强度越大。几种植物枝条在不同加载速度、不同直径、不同枝条水分变化影响下的抗拉生物力学特性既存在相同规律,又有差别,其内在原因还需要进一步的研究。

In order to reveal the biomechanical response mechanism of plants to wind erosion, to select prop- er windbreak trees, we took branches of six common plants in open-pit coal mine dump of Zhungeer, Inner Mongolia as the object. Indoor instantaneous limit tensile test was done on the ultimate tensile strength, concerning the branches size, loading speed and moisture conditions of the branches. The results showed that, the tensile strength of the tested plant branch with diameter range of 0-3 mm increased with increas- ing loading rate but decreasing diameter; the ultimate tensile strength order is Caragana Korshinskii （50.13 MPa）〉 Hippophae rhamnoides （37.27 MPa） 〉 Medicago sativa （30.25 MPa） 〉 Astragalus ad- surgens Pall （22.74 MPa）〉 Melilotus officinalis （22.22 MPa） ; the moisture loss rate of finer branches was higher, and the ultimate tensile strength of the finer branches was higher too when become dry.