Exploration of the Effects of Cohesive Forces in a Bead Pile

Ingrid Thvedt


The effects of the addition of cohesive inter-particle forces to a bead-pile was investigated by placing a bead pile composed of ferromagnetic beads in a magnetic field. Data was taken at four different field values and analyzed in order to create avalanche probability plots. The data was taken in the absence of a magnetic field matched data take previously at The College of Wooster under similar circumstances. When placed under a magnetic field, the probability of mid-sized avalanches decreased and the probability of very large avalanches increased, causing humps in the probability plots. Increasing the magnetic field caused these humps to become more defined and move to the right. At strong enough magnetic fields, the decrease in mid-sized avalanches becomes so great that the hump separates from the rest of the data completely.