甘薯成熟期秧蔓的机械物理特性参数研究

Study of Mechanical Property Parameters of Sweet Potato Vine in the Mature Period

为了给甘薯秧切割机构的设计及切割动力学分析提供甘薯秧的力学性能参数,以成熟期品种商薯19号甘薯秧为试验材料,在WDW-5E微机控制电子万能试验机上对甘薯秧进行了拉伸、压缩和弯曲试验,得到其拉伸弹性模量为179.77MPa,压缩弹性模量为15.34MPa,弯剪弹性模量为71.79MPa。运用材料力学及弹性力学理论,确定同性面横向剪切模量为6.00MPa,同性面泊松比为0.28,异性面泊松比为0.03。研究结果表明:甘薯秧的拉伸弹性模量与压缩弹性模量存在显著差异,甘薯秧表现为各向异性弹性材料模型。试验结果为建立甘薯秧蔓的力学模型进行甘薯秧蔓的切割研究提供了理论依据,对甘薯秧处理回收机切割装置的结构设计及作业参数确定等具有一定的指导和实际意义。

In order to provide mechanical property parameters for the design of sweet potato vine cutter and for the dynamic analysis of cutting process,this paper used the Shang Shu No. 19 sweet potato vine in harvesting period as the test material,carried out the tensile、compression and bending tests of sweet potato vine through the WDW-5 micro controlled electronic universal testing machine. The results show that the tensile elastic modulus is 179. 77 MPa,the compressive elasticmodulus is 15. 34 MPa,and the bending shear modulus is 71. 79 MPa. By using elastic mechanics and material mechanics theory,the transverse shear modulus of isotropic plane is 6. 00 MPa,the Poisson＇s ratio of isotropic plane is0. 28,and the Poisson＇s ratio of anisotropic plane is 0. 03. The results showed that there was a distinct difference between transverse tensile elastic modulus and radial compressive elastic modulus of sweet potato vine,so sweet potato vine is considered to be anisotropic material,when establishing the mechanical model,the anisotropic constitutive relations should be adopted. The results provide a theoretical basis for the establishment of the sweet potato vine finite element model and it is of great guidance and practical significance to the related structure design of the cutting parts of sweet potato vine crushing and returning machine.