Amorphous Media

There exists a robust theory, built from microscopic considerations, that explains the formation, behavior, and failure of crystalline solids. The same does not hold true for amorphous solids, which are structurally disordered. Disorder profoundly affects our theoretical understanding of the mechanics of amorphous solids. In the absence of periodicity, one cannot explain the microscopic origin of elastic constants. Additionally, in the absence of long range order, the notion of a topological defect so fundamental to crystalline plasticity is rendered meaningless for amorphous solids. The disorder that imparts additional strength to amorphous solids can also lead to their catastrophic failure. At the fundamental level, the problem stands at the frontier of Condensed Matter and Non-equilibrium Statistical Physics. Given a huge fraction of materials employed in daily use (including glasses, plastics, alloys, elastomers, and other composites) are amorphous in character, understanding their mechanics and failure carries huge signficance in Materials Physics applications.
Within the broad theme of disorder, our primary efforts have been directed towards experiments in frictional granular jamming, fracture of interfacial particle rafts, and molecular dynamics studies in two-dimensional aggregates.
  1. MM Bandi, T Tallinen and L Mahadevan, "Shock-driven jamming and periodic fracture of particulate rafts", Europhys. Lett. 96, 36008 (2011).
  2. MM Bandi, MK Rivera, F Krzakala and RE Ecke, "Fragility and hysteretic creep in frictional granular jamming", Phys. Rev. E. 87, 042205 (2013).
  3. Tamoghna Das, T Lookman and MM Bandi, "A minimal parameter description of morphological hierarchy in two-dimensional aggregates"Soft Matter 11, 6740 (2015).
  4. Naoki Iikawa, Mahesh M. Bandi and Hiroaki Katsuragi, "Structural evolution of a granular pack under manual tapping", J. Phys. Soc. Japan 84, 094401 (2015).
  5. N Iikawa, MM Bandi and H Katsuragi, "Sensitivity of Granular Force Chain Orientation to Disorder-induced Metastable Relaxation", Phys. Rev. Lett116, 128001 (2016).
  6. Tamoghna Das, T Lookman, and MM Bandi, "Morphology dictated heterogeneous dynamics in two-dimensional aggregates", Soft Matter 12, 9674 (2016). 
  7. Peco, W Chen, Y Liu, MM Bandi , JE Dolbow, and E Fried, "Influence of surface tension in the surfactant-driven fracture of closely-packed particulate monolayers Soft Matter 13, 5832 (2017).
  8. N Iikawa, MM Bandi, and H Katsuragi, "Force chain evolution in a two-dimensional granular packing compacted by vertical tappings." Phys. Rev. E. 97, 032901 (2018).
  9. MM Bandi, HGE Hentschel, I Procaccia, S Roy, and J Zylberg, "Training, Memory, and Universal Scaling in Amorphous Frictional Granular Matter" Europhys. Lett. 122, 38003 (2018).
  10. VS Akella, MM Bandi, HGE Hentschel, I Procaccia, and S Roy, "Force Distributions in Frictional Granular Media" Phys. Rev. E. 98, 012905 (2018).
  11. MM Bandi, P Das, O Gendelman, HGE Hentschel, and I Procaccia, "Universal scaling laws for shear induced dilation in frictional granular media" Granular Matter 21, 40 (2019).
  12. Tamoghna Das and MM Bandi, "Collective dynamics of two-dimensional aggregations with competing interactions"arXiv:1805.05011 (2018).