A cohesive granular material with tunable elasticity
Orateur : Arnaud Hemmerle
CINaM, Marseille
Résumé :
What are the common points between sandstone, ceramics, wet soils, and snowpack ? They can be very porous, while remaining cohesive, and controlling their mechanical and fracture properties can be crucial in many situations. Understanding such complex materials requires experiments on simplified systems, where one can finely study relations between various parameters.
We have recently developed a well-defined cohesive granular medium with a tunable elasticity, made of glass beads connected by solidified elastic bonds. This material is similar to wet sand, but where the liquid capillary bridges are replaced by a curable elastomer. I will first show how stiffness, shape, and porosity of the composite can be finely controlled, making it a model system for studies on cohesive porous media. Secondly, I will discuss yielding and fracture of the material, both studied using in-situ X-ray microtomography. Given the generic structure of this model system, the scaling laws between mechanical and geometrical properties that we derive here are of potential interest for other types of disordered cohesive granular media, such as paints or ceramics, for example.
Date et lieu : Mercredi 3 Mai à 15h, salle de séminaires IRPHE