Dynamical Heterogeneity in Shear-Jammed Granular Systems

¹ Department of Physics, Duke University, Durham, North Carolina 27708, USA
² Department of Physics, The Hong Kong University of Science and Technology, Hong Kong SAR, China
³ Laboratoire de Mécanique et Génie Civil, Université de Montpellier, CNRS, Montpellier 34090, France
⁴ Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai, China
⁵ State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^*** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^**** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 1 December 2025

Abstract

Granular suspensions can jam into solids under shear at densities below the isotropic jamming density. At sufficiently large shear stress, these shear-jammed structures undergo plastic flow through small deformations of the particles, contact breaking or slipping, and associated particle rearrangements. Although the shear jamming phenomenon has been extensively studied in recent decades, little is known about how shearjammed states evolve under steady shear. In this work, we report on systematic experiments on the evolution of a shear-jammed system using a recently developed multi-ring Couette shear device. This device imposes a linear shear profile on a layer of photoelastic discs, mimicking a two-dimensional suspension with a small Stokes number. We find that the displacements of the particles exhibit strong spatio-temporal correlations within the range of packing fractions where shear jamming occurs. The particle dynamics are quantified using the fourpoint susceptibility, which grows significantly as the packing fraction approaches the isotropic jamming point from below.