Mechanical Behavior Of Corn Stalk Pith: An Experimental And Modeling Study

Corn stalk pith (CSP) is porous and highly elastic, which makes it an excellent renewable packaging material with good cushioning properties. This paper investigated some important mechanical properties of corn stalk pith. The effects of moisture content, internodal position and variety on corn stalk pith's tensile strength and the Young's modulus were experimentally determined. A discrete element model (DEM) was developed to simulate the tensile testing process. It was found that the mechanical properties of corn stalk pitch were highly variable, with a tensile strength in the range of 0.2-1.35MPa, and Young's modulus 0.02-0.19GPa. The tensile strength of CSP increased with moisture content, while the Young's modulus showed the opposite tendency. From the DEM simulations of the load-displacement curve of CSP, the values of key mechanical properties in the DEM were determined: the normal stiffness coefficient k(n) = (0.5-3) x 10(6) N/m; the tangent stiffness coefficient ks= 1.0x10(6)N/m; the normal bonding coefficient n-bond = (5-50) N/m(3); and the tangential bonding coefficient s-bond = (10-50) N/m(3). These values provided important and necessary data for further analysing the mechanical properties of packaging materials made of CSP.