feed ical google calendar

(1) Presentation(s)

-

Lun. 15/05/2017 11:30 Salle RdC, Bâtiment 11, RdC

Séminaire
KOB Walter (Université de Montpellier)
Granular materials are complex fluids

(Matière Molle)


Sommaire:

Granular materials such as sand, powders, foams etc. are ubiquitous in our daily life, as well as in industrial and geotechnical applications. Although these disordered systems form stable structures if unperturbed, in practice they do relax because of the presence of unavoidable external influences such as tapping or shear. Often it is tacitly assumed that for granular systems this relaxation dynamics is similar to the one of thermal glass-formers, but in fact experimental difficulties have so far prevented to determine the dynamic properties of three dimensional granular systems on the particle level. This lack of experimental data, combined with the fact that in these systems the motion of the particles involves friction, makes it very challenging to come up with an accurate description of their relaxation dynamics. In this talk I will present results from X-ray tomography that allowed to determine the microscopic relaxation dynamics of hard granular ellipsoids that are subject to an oscillatory shear. This dynamics shows that on the particle level the dynamical behavior of granular systems are qualitatively different from the one of thermal glass-formers and instead more similar to the one of complex fluids.


Pour plus d'informations, merci de contacter Truzzolillo D.