Applied-force oscillations in avalanche dynamics.

Autor: McFaul LW; Department of Physics and Institute of Condensed Matter Theory, University of Illinois at Urbana Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA., Sparks G; Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, USA., Sickle J; Department of Physics and Institute of Condensed Matter Theory, University of Illinois at Urbana Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA., Uhl JT; Department of Mechanical Engineering, One Dent Drive, Bucknell University, Lewisburg, Pennsylvania 17837, USA., Wright WJ; Department of Mechanical Engineering, One Dent Drive, Bucknell University, Lewisburg, Pennsylvania 17837, USA.; Department of Chemical Engineering, One Dent Drive, Bucknell University, Lewisburg, Pennsylvania 17837, USA., Maaß R; Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, USA., Dahmen KA; Department of Physics and Institute of Condensed Matter Theory, University of Illinois at Urbana Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA.
Jazyk: angličtina
Zdroj: Physical review. E [Phys Rev E] 2020 May; Vol. 101 (5-1), pp. 053003.
DOI: 10.1103/PhysRevE.101.053003
Abstrakt: Until now most studies of discrete plasticity have focused on systems that are assumed to be driven by a monotonically increasing force; in many real systems, however, the driving force includes damped oscillations or oscillations induced by the propagation of discrete events or "slip avalanches." In both cases, these oscillations may obscure the true dynamics. Here we effectively consider both cases by investigating the effects of damped oscillations in the external driving force on avalanche dynamics. We compare model simulations of slip avalanches under mean-field dynamics with observations in slip-avalanche experiments on slowly compressed micrometer-sized Au specimens using open-loop force control. The studies show very good agreement between simulations and experiments. We find that an oscillatory external driving force changes the average avalanche shapes only for avalanches with durations close to the period of oscillation of the external force. This effect on the avalanche shapes can be addressed in experiments by choosing suitable specimen dimensions so that the mechanical resonance does not interact with the avalanche dynamics. These results are important for the interpretation of avalanche experiments with built-in oscillators, and for the prediction and analysis of avalanche dynamics in systems with resonant vibrations.
Databáze: MEDLINE