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Updated: May 11, 2026
06:07
Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
Complex oscillatory yielding of model hard-sphere glasses.
N Koumakis1, J F Brady, G Petekidis
1FORTH/IESL and Department of Materials Science and Technology, University of Crete, 71110 Heraklion, Greece.
Physical Review Letters
|May 18, 2013
Summary
The yielding behavior of hard sphere glasses depends on oscillation frequency. Brownian motion dominates at low frequencies, while shear-induced collisions are key at high frequencies, influencing the material
Area of Science:
- Materials Science
- Soft Matter Physics
- Rheology
Background:
- Hard sphere glasses exhibit complex yielding behavior under shear.
- Understanding the interplay of Brownian motion and shear-induced phenomena is crucial.
Purpose of the Study:
- To investigate the yielding mechanisms of hard sphere glasses under large-amplitude oscillatory shear.
- To probe the frequency dependence of Brownian motion and shear-induced diffusion.
Main Methods:
- Experimental rheology to measure stress, structure, and dynamics.
- Brownian dynamics simulations to model particle behavior.
Main Results:
- At low frequencies, Brownian-motion-assisted cage escape dominates, causing a peak in G''.
- At high frequencies, shear-induced collisions become dominant, also linked to a G'' peak.
- A novel double peak in G'' at intermediate frequencies reflects both mechanisms.
- Structural anisotropy at high frequencies leads to stress drops after strain reversal.
Conclusions:
- Yielding in hard sphere glasses is frequency-dependent, involving distinct mechanisms.
- The study reveals a new double-peak phenomenon in G'' for hard sphere glasses.
- Structural anisotropy plays a significant role in the yielding response at high frequencies.
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