Hot Spots in an Athermal System

Axelle Amon (1) , van Bau Nguyen (2) , Ary Bruand (3) , Jérôme Crassous (1) , Eric Clément (2)

1 IPR - Institut de Physique de Rennes
2 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
3 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327

We study experimentally the dynamical heterogeneities occurring at slow shear, in a model amorphous glassy material, i.e., a 3D granular packing. The deformation field is resolved spatially by using a diffusive wave spectroscopy technique. The heterogeneities show up as localized regions of strong deformations spanning a mesoscopic size of about 10 grains and called the "hot spots." The spatial clustering of hot spots is linked to the subsequent emergence of shear bands. Quantitatively, their appearance is associated with the macroscopic plastic deformation, and their rate of occurrence gives a physical meaning to the concept of "fluidity," recently used to describe the local and nonlocal rheology of soft glassy materials.

Domains: Other

Axelle Amon, van Bau Nguyen, Ary Bruand, Jérôme Crassous, Eric Clément. Hot Spots in an Athermal System. Physical Review Letters, 2012, 108, pp.135502-1 - 135502-5. ⟨10.1103/PhysRevLett.108.135502⟩. ⟨insu-00684411⟩