Crackling to periodic transition in earthquake dynamics: a granular stick-slip experiment
ORAL
Abstract
We perform a stick-slip experiment to characterize the dynamics of sheared granular media. In our experiment, a constant speed stage pulls a slider which rests on a vertical bed of circular photo-elastic particles in a 2D system. The stage is connected to the slider by a spring.
We measure the force applied to the slider using a force sensor attached to the spring. This force provides a global measure of the shear stress. From a more local point of view and by using a high speed camera and the photo-elastic properties of our particles, we characterize the local stress change in the granular medium. Using signal analysis of these global and local measures, we can identify a crackling to periodic transition as we change driving rate and system stiffness. We provide a phase diagram of different regimes and the scaling laws of the transition. we also study the effect of other parameters such as global pressure and system size and how global and local signals are related to each other.
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Presenters
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Aghil Abed Zadeh
Phsyics, Duke University
Authors
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Aghil Abed Zadeh
Phsyics, Duke University
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Jonathan Bares
CNRS, Duke University; Universit'e de Montpellier, Physics, Duke University, Université de Montpellier
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Robert Behringer
Duke Univ, Physics, Duke University, Dept. of Physics, Duke Univ, Duke University, Department of Physics, Duke Univ, Physics Department, Duke Univ., Phsyics, Duke University, Physics Department, Duke Univ