Brittle and Ductile Yielding in Soft Materials

Explore the physics of yielding in soft materials through this 37-minute talk by Simon Rogers, part of the Thematic Programme on "Non-equilibrium Processes in Physics and Biology" at the Erwin Schrödinger International Institute for Mathematics and Physics. Delve into the spectrum of yielding behaviors, from gradual ductile transitions to abrupt brittle changes, and their importance in biological, environmental, and industrial materials. Examine the key rheological signatures of brittle yielding, including stress overshoots in steady-shear-startup tests and steep increases in loss modulus during oscillatory amplitude sweeps. Learn about a new continuum model for yield stress materials that introduces the "brittility factor," which accounts for the varying yielding behaviors. Understand how this parameter affects the contribution of recoverable deformation to plastic deformation and impacts the rate of yielding. Compare model predictions with real-world results from various yield stress fluids, demonstrating the broad applicability of the brittility concept. Gain insights into how the brittility of soft materials critically influences the yielding transition rate and provides a valuable tool for understanding material behavior under different loading conditions.