Structural and Topological Nature of Plasticity in Sheared Granular Materials

Abstract

Upon mechanical loading, granular materials yield and undergo plastic deformation. The nature of plastic deformation is essential for the development of the macroscopic constitutive models and the understanding of shear band formation. However, we still do not fully understand the microscopic nature of plastic deformation in disordered granular materials. Here we used synchrotron X-ray tomography technique to track the structural evolutions of three-dimensional granular materials under shear. We establish that highly distorted coplanar tetrahedra are the structural defects responsible for microscopic plasticity in disordered granular packings. The elementary plastic events occur through flip events which correspond to a neighbor switching process among these coplanar tetrahedra (or equivalently as the rotation motion of 4-ring disclinations). These events are discrete in space and possess specific orientations with the principal stress direction.

arXiv comment26 pages, 11 figures, 2 tables, to be published in Nature Communications

References in corpus (12)

• Dynamics of Viscoplastic Deformation in Amorphous Solids
• On dense granular flows
• Vibrational modes identify soft spots in a sheared disordered packing
• Deformation and Failure of Amorphous Solidlike Materials
• Granular materials flow like complex fluids
• Marginal Stability in Structural, Spin and Electron Glasses
• Rearrangements and Dilatancy for Sheared Dense Materials
• Statistics of Bubble Rearrangements in a Slowly Sheared Two-dimensional Foam
• Reversible plasticity in amorphous materials
• The structural origin of the hard-sphere glass transition in granular packing
• Soft modes and non-affine rearrangements in the inherent structures of supercooled liquids
• Topological rearrangements and stress fluctuations in quasi-two-dimensional hopper flow of emulsions

Cited by in corpus (13)

• Topology of vibrational modes predict plastic events in glasses
• X-ray tomography investigation of cyclically sheared granular materials
• Experimental Test on Edwards Volume Ensemble of Tapped Granular Packings
• Yielding and hardening of flexible fiber packings during triaxial compression
• Experimental identification of topological defects in 2D colloidal glass
• Clustering of negative topological charge precedes plastic failure in 3D glasses
• Contact network changes in ordered and disordered disk packings
• Origin of two distinct stress relaxation regimes in shear jammed dense suspensions
• Geometry-controlled phase transition in vibrated granular media
• Phonons in stringlet-land and the boson peak
• Hedgehog topological defects in 3D amorphous solids
• Geometric indicators of local plasticity in glasses measured by scanning small-beam diffraction
• Influence of Roughness on Granular Avalanches