IRG1: Rearrangements & Softness in Disordered Solids (2017-2023)

IRG Leaders: Paulo E. Arratia & Douglas J. Durian   

Senior Investigators: Robert W. Carpick, Zahra Fakhraai, Daeyeon Lee, Andrea J. Liu, Robert A. Riggleman, Kevin T. Turner, Arjun G. Yodh

Collaborators: Danielle S. Bassett, John C. Crocker, Eleni Katifori, Christopher B. Murray   

IRG-1 aims to develop fundamental understanding of the organization and proliferation of localized particle-scale rearrangements in disordered solids deformed just beyond the onset of yield, and thereby identify strategies for controlling nonlinear mechanical response and enhancing toughness. The materials studied by the team span a wide range of length scales from amorphous carbon and atomic/molecular glasses, to nanoparticles and colloids, to macroscopic bubbles and grains. When pushed beyond yield, some materials crack or shatter due to rearrangements that collect along planes, whereas others flow smoothly because rearrangement events remain separated. New theoretical concepts, some based on machine learning, will be developed to understand this dramatic difference, and these theories will be tested by atomistic simulations and experiments on systems for which it is possible to measure microstructure versus time during a large imposed deformation. Ultimately, these factors will be optimized to widen the window between yield and failure and hence to improve toughness.

Highlights for IRG1

Toughening Infiltrated Nanoparticle Packings: Role of Bridging and Entanglement
Kevin Turner, Daeyeon Lee, University of Pennsylvania
Uncovering the Surprising Nature of Glassy Energy Landscapes
John C. Crocker (CBE) and Robert A. Riggleman (CBE), University of Pennsylvania
The Perpetual Fragility of Creeping Hillslopes
Douglas J. Jerolmack, Paulo E. Arratia, & Robert A. Riggleman
Interaction Range Can be Tuned to Control Failure Mode in a Model Experimental Disordered Solid
Douglas J. Durian, Andrea J. Liu, and Robert A. Riggleman, University of Pennsylvania
Scaling relationship between microstructure and relaxation in cyclic sheared 2D disordered colloids
Paulo E. Arratia & Arjun Yodh, University of Pennsylvania
Formation of Stable and Hierarchical Particle Aggregates by “Solid Bridging”
A. Seiphoori, X-G Ma, P.E. Arratia, D. Jerolmack, University of Pennsylvania
Mechanical Properties of Disordered Packings Under Confinement
H. Wang, Y. Qiang, A. A. Shamsabadi, P. Mazumder, K. T. Turner, D. Lee, Z. Fakhraai, University of Pennsylvania
Machine Learning & Softness: Characterizing local structure and rearrangements in disordered solids
Paulo E. Arratia & Douglas J. Durian, University of Pennsylvania
Universal Signatures of Plasticity in a Wide Range of Disordered Solids
P.E. Arraita, R.W. Carpick, D.J. Durian, Z. Fakhraai, D. Lee, A.J. Liu, R. Riggleman, K.T. Turner, A.G. Yodh