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Abstract. Discrete element method (DEM) is a useful computational technique for simulation of a wide range of systems of bulk granular materials. Introducing new methods for calibration of DEM to improve its prediction accuracy is an ongoing field of study. Developing a DEM calibration methodology to predict grain dynamics in machine systems has been limited especially under varying grain moisture content (MC). The objective of this study was to determine the effect of MC on modeling the frictional and cohesive behaviors of corn at three moisture content levels (12%, 15%, and 20%) using DEM.

The Hertz-Mindlin with JKR cohesion contact model was used to simulate the frictional and cohesive behavior of corn-corn and corn-wall interactions. The effect of moisture content on the dynamic behavior of grains at loose and confined states was investigated. The static Angle of Repose (AOR) and direct shear test were assumed to represent the loose and confined states, respectively. Parametric sensitivity studies were conducted on both experimental and DEM simulation which showed a statistically significant effect of MC on the response variables from bucket AOR and direct shear tests. After the optimal DEM input parameter values matching the angle of repose and direct shear bulk responses were obtained, the MC effect on DEM input parameters were studied and concluded that increase in corn MC causes increase in corn‘s DEM Young modulus and corn-corn static friction coefficient while decreasing the corn-corn rolling friction.