Microscopic dynamics and failure precursors of a gel under mechanical load Auteur(s): Aime S., Ramos L., Cipelletti L. (Article) Publié: Proceedings Of The National Academy Of Sciences Of The United States Of America, vol. 115 p.3587 (2018) Texte intégral en Openaccess : Ref HAL: hal-01904079_v1 Ref Arxiv: 1804.01810 DOI: 10.1073/pnas.1717403115 WoS: 000429012500051 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 19 Citations Résumé: Material failure is ubiquitous, with implications from geology to everyday life and material science. It often involves sudden, unpredictable events, with little or no macroscopically detectable precursors. A deeper understanding of the microscopic mechanisms eventually leading to failure is clearly required, but experiments remain scarce. Here, we show that the microscopic dynamics of a colloidal gel, a model network-forming system, exhibit dramatic changes that precede its macroscopic failure by thousands of seconds. Using an original setup coupling light scattering and rheology, we simultaneously measure the macroscopic deformation and the microscopic dynamics of the gel, while applying a constant shear stress. We show that the network failure is preceded by qualitative and quantitative changes of the dynamics, from reversible particle displacements to a burst of irreversible plastic rearrangements. Commentaires: . Réf Journal: PNAS 115, 3587 (2018) |