Determination of Parameters of a Tangential Contact Force Model for Viscoelastic Spheroids (fruits) using a Rheometer Device

This paper describes a method to experimentally determine the parameters of a tangential contact force model for spherical viscoelastic objects using a rheometer. The tangential contact force model is a necessary component of a discrete element model to simulate various granular matter systems. In this study, the discrete element model is being applied to simulate postharvest unit operations for fruits or similar agricultural produce. In the first part of the paper, a description of the contact force model is developed by extending the existing models for tangential contact of elastic spheres to include a viscous component. The second part describes the experiments performed and the associated results. The parameters under investigation are the material elastic shear modulus, the material viscosity and the friction coefficient.