Two examples of granular materials “engineered” for strength: Granular crystals, entangled matter
Abstract
Over the past two decade our research group has been focusing so far on the development of new structural materials that combine high strength and high toughness. We are particularly interested in fully dense “architectured” materials and structures made from regular building blocks of controlled shape and size. In these designs - some of then inspired by nature - the interplay of between stiff and strong building block, geometry and weaker interfaces gives rise to a wealth of tunable mechanisms and precise structural properties. In our effort to expand some of these designs, our research trajectory recently intersected the field of granular mechanics. Our playground now is still geometry, mechanics and structural properties, but we now call our building blocks grains or particles, and we use vibrations as an assembly tool.
In this talk I will discuss two types of “engineered” granular materials of interest to us. The first one is fully dense granular crystals made of space filling polyhedral grains, and which are 10 times stronger than traditional granular materials. These granular crystals display a rich set of mechanisms which we are investigating using experiments and discrete element models: Nonlinear deformations, crystal plasticity reminiscent of atomistic mechanisms, geometric strain hardening, micro-buckling. Our other granular material of interest is engineered entangled matter. I will discuss the experiments we use to measure entanglement and strength as function of particle geometry, and how we are capturing entanglement mechanisms at multiple length scales using Monte Carlo simulations and discrete element models. We envision that these “engineered” granular materials will offer combinations of strength, toughness and recyclability that will rival the capabilities of existing structural materials.
Over the past two decade our research group has been focusing so far on the development of new structural materials that combine high strength and high toughness. We are particularly interested in fully dense “architectured” materials and structures made from regular building blocks of controlled shape and size. In these designs - some of then inspired by nature - the interplay of between stiff and strong building block, geometry and weaker interfaces gives rise to a wealth of tunable mechanisms and precise structural properties. In our effort to expand some of these designs, our research trajectory recently intersected the field of granular mechanics. Our playground now is still geometry, mechanics and structural properties, but we now call our building blocks grains or particles, and we use vibrations as an assembly tool.
In this talk I will discuss two types of “engineered” granular materials of interest to us. The first one is fully dense granular crystals made of space filling polyhedral grains, and which are 10 times stronger than traditional granular materials. These granular crystals display a rich set of mechanisms which we are investigating using experiments and discrete element models: Nonlinear deformations, crystal plasticity reminiscent of atomistic mechanisms, geometric strain hardening, micro-buckling. Our other granular material of interest is engineered entangled matter. I will discuss the experiments we use to measure entanglement and strength as function of particle geometry, and how we are capturing entanglement mechanisms at multiple length scales using Monte Carlo simulations and discrete element models. We envision that these “engineered” granular materials will offer combinations of strength, toughness and recyclability that will rival the capabilities of existing structural materials.
Practical information
- Informed public
- Free
Organizer
- Prof. Dimitrios Lignos (IIC), Prof. Konstantinos Karapiperis (LMD)
Contact
- Prof. Konstantinos Karapiperis