A computational study by Professor Emanuela Del Gado's research group, published in Nature Communications, provides new insights on the dynamics of aging in soft, amorphous solids. Aging occurs when nanoscale particles or aggregates in the material undergo structural rearrangement, affecting the mechanical performance of the materials. While it has generally been accepted that the process is gradual and occurs over long time scales, recent experiments have suggested intermittency and the possibility of abrupt reorganization of large domains under certain conditions. Using molecular dynamics simulations, the Del Gado team studied time scales for stress relaxation through both thermal and elastic fluctuations. The simulations revealed that when thermal fluctuations are weak, elastically-driven stress fluctations can give rise to fast and intermittent dynamics. The study offers a unifying framework for understanding microscopic dynamics in a wide range of soft solids.
Dr. Mehdi Bouzid, a postdoctoral fellow in the Del Gado group, was lead author on the paper. Lucas Vieira Barbosa, an undergraduate physics exchange student from Brazil, developed specialized visualization software for the project.
- M. Bouzid, J. Colombo, L. Vieira Barbosa, and E. Del Gado, Elastically driven intermittent microscopic dynamics in soft solids, Nat. Commun. 8, 15846 (2017). doi:10.1038/ncomms15846
Del Gado team makes breakthrough on abrupt aging, Georgetown College News