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Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
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Local shear transformations in deformed and quiescent hard-sphere colloidal glasses
K E Jensen1, D A Weitz2, F Spaepen3
1Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 7, 2014
Summary
Shear transformation zones are active in colloidal glasses, even without applied stress. Applied shear increases their activity and irreversibility, leading to plastic deformation upon stress reversal.
Area of Science:
- Materials Science
- Soft Matter Physics
- Rheology
Background:
- Colloidal glasses exhibit complex behavior under deformation.
- Understanding particle dynamics is crucial for characterizing material properties.
Purpose of the Study:
- To investigate the existence and activity of shear transformation zones (STZs) in colloidal glasses under deformation.
- To analyze the impact of applied shear and stress reversal on STZs and particle dynamics.
Main Methods:
- Deformation experiments on monodisperse, hard-sphere colloidal glass.
- Simultaneous tracking of individual particle trajectories using confocal microscopy.
- Analysis of spatial autocorrelations of local shear strain.
Main Results:
- STZs are active in both sheared and quiescent colloidal glasses.
- Applied shear accelerates STZ development and increases irreversibility.
- Stress reversal leads to partial elastic recovery and subsequent plastic deformation.
Conclusions:
- STZs play a significant role in the mechanical response of colloidal glasses.
- The dynamics of STZs are influenced by applied shear and stress history.
- STZs contribute to the observed plastic deformation and limited elastic recovery.
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