Vibrations of Jammed Disk Packings with Hertzian Interactions

Granular media has complex vibrational properties. Contact breaking and Hertzian interactions between grains can both give rise to nonlinear vibrational response of static granular packings. Through molecular dynamics simulations in model granular packings that interact via Hertzian spring potentials, we show that while Hertzian interactions lead to weak nonlinearities in the vibrational behavior (e.g. the generation of harmonics of the eigenfrequencies of the dynamical matrix), the vibrational response of static packings with Hertzian contact interactions is dominated by contact breaking as found for systems with repulsive linear spring interactions.