莲藕力学特性的试验研究

Biomechanics of lotus root

以藕身含水率82.78%~86.69%的"鄂莲5号"为研究对象,采用TMS-Pro质构仪和RGM-3005微机控制全数字化电子式万能材料试验机对其藕身果肉部分、藕段截面及单节藕段进行压缩试验,对藕节进行弯曲和拉伸试验。结果表明:藕身果肉部分的抗压强度为0.908~1.750 MPa,弹性模量为0.451~2.529 MPa,同一藕段藕身果肉靠近表层部分相同方向的抗压强度和弹性模量均大于心部,同一藕段藕身果肉的轴向弹性模量大于径向,藕身果肉部分存在各向异性特性;藕节平均抗弯强度从藕节Ⅰ至藕节Ⅲ分别为1.337、1.227、1.153 MPa;藕节平均拉伸强度从藕节Ⅰ至藕节Ⅲ分别为0.546、0.560、0.551 MPa,藕节抗弯强度和拉伸强度均与直径正相关。

In order to reduce mechanical injury during harvesting the lotus roots,Elian No.5with moisture content of lotus rhizome ranging from 82.78%-86.69% was used.Compression test for lotus rhizome pulp,segments and the whole lotus,bending and stretch test for joints of lotus roots was conducted with the TMS-protexture analyzer and the RGM-3005 accurate micro-controlled electronic universal testing machine.The results showed that the compressive strength of lotus rhizome pulp was 0.908-1.750 MPa.The elastic modulus was 0.451-2.529 MPa.The values of both compressive strength and elastic modulu of pulp closed to edge were bigger than that of core along the same direction.The value of elastic modulu along axial was bigger than that of radial in the same segments,indicating that lotus belongs to anisotropic materials.The average value of joints' bending strength from the first to the second was 1.337,1.227,and 1.153 MPa,respectively.The average value of joints' stretch strength from the first to the second was 0.546,0.560,and 0.551 MPa,respectively.There was a positive correlation between bending force and diameter,stretch force and diameter.It will provide theoretical basis for studying water erosion parameters of lotus root with digging machine.