Sheared Amorphous Packings Display Two Separate Particle Transport Mechanisms
ORAL
Abstract
Shearing granular materials induces non-affine displacements. Such non-affine displacements have been studied extensively, and are known to correlate with plasticity and other mechanical features of amorphous packings. A well-known example is shear transformation zones as captured by the local deviation from affine deformation, D2min. We analyze sheared frictional athermal disc packings and show that there exists at least one additional mesoscopic transport mechanism that superimposes itself on top of local diffusive motion. We evidence this second transport mechanism in a homogeneous system via a diffusion tensor analysis and show that when this second mesoscopic transport is corrected for, the trace of the diffusion tensor equals the classic D2min. The new transport mechanism is consistently observed over a wide range of volume fractions and even for particles with different friction coefficients and is consistently observed also upon shear reversal, hinting at its relevance for memory effects.
*We acknowledge support from NSFC Grant No. 41672256 and NSF Grant No. DMR1809762.
–
Presenters
-
Hu Zheng
- Department of Geotechnical Engineering, Tongji University
- Tongji University
- Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai, China
- Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, China