Intruder dynamics in a 2D granular system: Effects of dynamic and static basal friction*

We discuss the results of simulations of an intruder pulled through a 2D granular system by a spring, using a model designed to lend insight into the experimental findings described by Kozlowski et al. [Phys. Rev. E 100, 032905 (2019)]. In that previous study, the presence of basal friction between the grains and the base was observed to change the intruder dynamics from clogging to stick–slip. Here we first show that our simulation results are in excellent agreement with the experimental data for a variety of experimentally accessible friction coefficients governing interactions of particles with each other and with boundaries. We then use simulations to explore a broader range of parameter space, focusing on the friction between the particles and the base. We consider a range of friction coefficients, which are difficult to vary smoothly in experiments. The simulations show that dynamic friction strongly affects the stick–slip behavior when the coefficient is decreased below 0.1, while static friction plays only a marginal role.