The Study Of The Corn Stalk Mechanical Properties And Analysis Of Blade

Under the background of studying harvest technology， the mechanical model of the corn and themechanical properties and straw cutting blades is studied in this paper. It provides technology support todesign the straw cutting blades. The main research contents and results are as follows:(1)Corn stalk is mainly composed of skin， core and sections. They have its physical and mechanicalproperties. In this paper corn stalk is the research object， which can be abstracted to the shaft structurewith skin， corn and sections. All the parts are transversely isotropic material， so the corn stalks arecomposed of three different transversely isotropic materials. With the mechanics theory of the compositematerials and the mechanics model of the transversely isotropic materials， we can obtain the displacementequations， which is considered as the linear partial differential equations. There are three methods insolving the partial differential equations， but among them the Finite Element Method is the best.(2)By the mechanics theory of the composite materials， the skin， core， sections and the corn stalkare tested through three traditional methods: Tensile test， compression test， twisting test. We can obtaintheir load-displacement curve. With the help of data processing software， we can get many elasticparameters of the core and the corn stalk， such as the tensile elastic modulus， compressive elasticmodulus， twisting elastic modulus， the maximum tensile strength， the maximum compressive strength，the maximum twisting elastic modulus and so on. There are many elastic parameters of the transverselyisotropic materials. But some of them could not be obtained through the experiment. By comparing withthe characteristics and parameters of other biological materials， all the elastic parameters can be obtainedat last.(3)The corn FEM model is established with the average geometric model， it adopts the ANSYSsoftware to simulate the core with the torque load. We can obtain the stress and the displacement in it. Thesimulation is consistent with the experiment: the central straw fibers had maximum displacement which isfirst to broken.(4)Basting on the productions，processing requirements and associated technical indications，we cananalysis the system function and design the blade. With the cutting experiments determine the number ofstraw blade and make sure that the blades length is268mm， width100mm， thickness3.5mm， angle of30°and slid cutting angle30°.