MechE Colloquium: Failure in granular materials : from localized events to shear bands
Event details
| Date | 28.02.2023 |
| Hour | 12:00 › 13:00 |
| Speaker | Prof. Jérôme Crassous, Institute of Physics, University of Rennes |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
Abstract: Disordered materials (glasses, granular media, foams, etc.) usually deform in heterogeneous ways. The deformation of materials is concentrated in localized areas, such as shear bands. The mechanisms responsible for this localization remain unclear and debated.I will show in this seminar experimental results obtained on the formation and the dynamic of shear bands in a granular medium.
In a first part, I will present an original method for measuring very small deformations using dynamic light scattering. In the case of granular media, incremental deformation maps are obtained for average deformations of the order of a few ppm. I will then discuss the organization of the plastic deformation before the deformation localization occurs. Discrete reorganization events happens, the nature of which will be specified. Finally, I will discuss the deformation fluctuations within an established shear band. Discrete events can be defined, with statistical properties identical to those of earthquake crusts.
Biography: Jérôme Crassous is a professor of Physics at the University of Rennes. After a PhD on nano-wetting, he was an assistant professor at the ENS de Lyon where he worked on adhesion and lubrication force measurements. At the University of Rennes, he developed techniques for measuring microstrain based on dynamic light scattering, and used it to characterize deformations of granular materials. His current research interests include plasticity of granular materials, and collective effects in frictional media.
In a first part, I will present an original method for measuring very small deformations using dynamic light scattering. In the case of granular media, incremental deformation maps are obtained for average deformations of the order of a few ppm. I will then discuss the organization of the plastic deformation before the deformation localization occurs. Discrete reorganization events happens, the nature of which will be specified. Finally, I will discuss the deformation fluctuations within an established shear band. Discrete events can be defined, with statistical properties identical to those of earthquake crusts.
Biography: Jérôme Crassous is a professor of Physics at the University of Rennes. After a PhD on nano-wetting, he was an assistant professor at the ENS de Lyon where he worked on adhesion and lubrication force measurements. At the University of Rennes, he developed techniques for measuring microstrain based on dynamic light scattering, and used it to characterize deformations of granular materials. His current research interests include plasticity of granular materials, and collective effects in frictional media.
Practical information
- General public
- Free