Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 46: Complex Fluids and Soft Matter (joint session DY/CPP)

CPP 46.11: Vortrag

Dienstag, 17. März 2020, 12:15–12:30, ZEU 160

Universal properties of creep flow — •Marko Popović¹, Tom de Geus¹, Wencheng Ji¹, Alberto Rosso², and Matthieu Wyart¹ — ¹Institue of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland — ²LPTMS, CNRS, Univ.Paris-Sud, Universite Paris-Saclay, 91405 Orsay, France

Amorphous solids, such as atomic glasses, colloidal suspensions, granular matter or foams, begin to deform plastically when exposed to external stress Σ. Steady state flow of these materials in absence of thermal fluctuations is usually described as є ∼ (Σ − Σ_c)^β for stresses above critical stress Σ_c and vanishes below it, while in presence of thermal fluctuations flow persists below Σ_c but is exponentially suppressed. The transient plastic deformation, called creep flow, is much less understood despite its importance in practical applications. Creep flow often displays a power-law decay in time є∼ t^−µ after which it can either arrest or eventually yield at fluidisation time τ_f. In recent years various numerical values and/or laws have been suggested for the exponent µ and time τ_f in particular experimental or numerical studies. We propose that mechanism underlying creep flow is the same as that of the steady state flow, which allows us to predicts parameters µ and τ_f of creep flow in terms of the steady state flow parameters, both in athermal and thermally activated systems. We successfully tested all our predictions using different mesoscopic elasto-plastic models of amorphous solids and found them to be consistent with published experimental results.