VIDEO TRACKING FOR EXPERIMENTAL VALIDATION OF DISCRETE ELEMENT SIMULATIONS OF LARGE DISCONTINUOUS DEFORMATIONS

The discrete element method (DEM) simulates large discontinuous deform ations as a natural outcome of discrete particle interactions. The met hod is well suited for problems such as plowing, penetration and hoppe r flows. However, verification of DEM simulations has been largely lim ited to comparisons with laboratory stress-strain diagrams of two dime nsional simulations of at most a few thousand ideally-shaped particles . This paper presents an automated video tracking and digital image an alysis system that has been developed to obtain soil particle displace ment fields and velocities fr am small-scale laboratory experiments. A three-dimensional simulation of a laboratory plowing experiment is pe rformed in which a one-to-one correspondence is achieved between the n umber of particles and their size distribution in simulation and physi cal experiment. The data obtained from the video tracking system are u sed to evaluate the qualitative and quantitative ability of the simula tion to model the experiment kinematics. (C) 1997 Elsevier Science Ltd .