Paper Number
SC11 

Session
Suspensions and Colloids

Title
Rigidity percolation in shear thickening suspensions

Presentation Date and Time
October 10, 2022 (Monday) 2:50

Track / Room
Track 1 / Sheraton 4

Authors (Click on name to view author profile)

1. Goyal, Abhay (National Institute of Standards and Technology, Infrastructure Materials Group)
2. Martys, Nicos (National Institute of Standards and Technology, Infrastructure Materials Group)
3. Del Gado, Emanuela (Georgetown University, Department of Physics)

Author and Affiliation Lines (in printed abstract book)
Abhay Goyal¹, Nicos Martys¹ and Emanuela Del Gado^2
1Infrastructure Materials Group, National Institute of Standards and Technology, Gaithersburg, MD; ²Department of Physics, Georgetown University, Washinton, DC 20057

Speaker / Presenter 
Del Gado, Emanuela

Keywords
computational methods; colloids; suspensions

Text of Abstract
Shear thickening is a prevalent phenomenon in dense suspensions that needs to be understood and controlled for a variety of industrial applications. Generally, discontinuous shear thickening is associated with a sharp charge in the nature of particle contacts (from lubricated to frictional). However, it is also well-known that there are very large fluctuations of the stress in a thickened suspension, yet this does not seem to be coupled to any major microstructural changes. To identify the microstructural underpinnings of this behavior, we perform simulations of sheared dense suspensions of varying sizes. By analyzing particle contact networks, we identify a subset of "constrained" particles that contribute directly to the macroscopic shear stress. The sharp rise in viscosity and the large stress fluctuations can both be explained by the growth and percolation of this "constrained" particle network--a direct analogy to rigidity percolation in shear jamming systems. Finally, a finite size scaling analysis confirms this is a percolation phenomenon and allows us to investigate the critical behavior.