(2022-04-21) Pugnaloni, Luis; Carlevaro, Manuel; Kozlowski, Ryan; Zheng, Hu; Kondic, Lou; Socolar, Joshua E. S.
Experiments and simulations of an intruder dragged by a spring through a two-dimensional annulus of granular
material exhibit robust force fluctuations. At low packing fractions (φ < φ0), the intruder clears an open channel.
Above φ0, stick-slip dynamics develop, with an average energy release that is independent of the particle-particle and particle-base friction coefficients but does depend on the width W of the annulus and the diameter D of the intruder. A simple model predicts the dependence of φ0 on W and D, allowing for a data collapse for the
average energy release as a function of φ/φ0. These results pose challenges for theories of mechanical failure in amorphous materials.
