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Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
Transient behavior of a model fluid under applied shear.
Dino Costa1, Alessandro Sergi, Mauro Ferrario
1Dipartimento di Fisica e di Scienze della Terra, Università degli Studi di Messina Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
The Journal of Chemical Physics
|May 17, 2013
Summary
This study uses dynamical non-equilibrium molecular dynamics to investigate the transient behavior of soft repulsive spheres under shear. The method accurately captures the time-dependent viscous response, including a characteristic peak, and validates steady-state viscosity values.
Area of Science:
- Soft Matter Physics
- Fluid Dynamics
- Computational Physics
Background:
- Understanding transient fluid behavior under shear is crucial for material science.
- Non-equilibrium molecular dynamics (NEMD) is a powerful tool for simulating fluid systems.
- Previous studies have explored transient regimes in various fluid systems.
Purpose of the Study:
- To investigate the transient behavior of a model fluid composed of soft repulsive spheres under planar uniform shear.
- To validate the use of a specific dynamical NEMD method for studying time-dependent viscous response.
- To analyze the characteristic peak and relaxation behavior of the shear response.
Main Methods:
- Dynamical non-equilibrium molecular dynamics (NEMD) method.
- Application of a configurational thermostat (Braga and Travis, 2005) for temperature control.
- Simulation of soft repulsive spheres subjected to planar uniform shear.
Main Results:
- The dynamical NEMD method successfully captures the transient viscous response over a wide range of shear rates.
- The system exhibits an initial rapid increase in response, followed by a pronounced peak and relaxation to a plateau.
- The plateau viscosity values accurately reproduce those obtained from standard steady-state NEMD.
Conclusions:
- The employed dynamical NEMD method is effective for studying transient shear flow in soft matter systems.
- The observed peak in the transient response is a key characteristic of this fluid model under shear.
- This approach provides a reliable way to determine steady-state viscosity from transient simulations.
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