Jérôme Crassous

Jérôme Crassous

Professor of Physics

Shear bands formation.

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Published:

Deformation localization in granular media and amorphous plasticity Collaboration: J.Weiss and D. Marsan, ISTERRE (Grenoble, Chambéry). E. Clément PMMH.

One of the main aims of our work is to understand the nature and organization of plastic flow in a deforming amorphous medium, and to study the approach to fracture in these media. One of the original features of our experimental approach is the use of an interferometric method for measuring microstrain that we have developed. Using stacks of glass microspheres as a model amorphous material, we have demonstrated that plastic flow, observed well before fracture, has a heterogeneous, intermittent structure that spontaneously organizes itself into ephemeral microbands. This structure confirms the relevance of the theoretical scenarios currently proposed to describe the plasticity of amorphous materials in terms of cascades of plastic events whose interaction is governed by the material’s elasticity. We have shown experimentally and numerically that this description in terms of an effective elastic medium is relevant for an assembly of rigid grains in frictional contact [Houdoux, PRE2018]. As the system approaches fracture, the plastic flow behavior becomes multiscale. We have shown experimentally that the appearance of a shear band at the sample scale corresponds to a symmetry break in the organization of the plasticity field. In collaboration with E. Clément, we have studied creep flows and their activation under the effect of mechanical perturbations.

https://doi.org/10.1103/PhysRevE.98.022905

https://doi.org/10.1103/PhysRevE.94.022907

https://doi.org/10.1103/PhysRevE.92.020201

https://doi.org/10.1103/PhysRevLett.112.246001

https://doi.org/10.1103/PhysRevLett.108.135502

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