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Edwards thermodynamic framework controls density segregation in cyclically sheared granular materials
Haiyang Lu1, Houfei Yuan1, Shuyang Zhang1
1Shanghai Jiao Tong University, School of Physics and Astronomy, Shanghai 200240, China.
Physical Review. E
|July 24, 2026
Summary
Granular segregation, driven by density differences, can be explained by a thermodynamic framework. This model uses a segregation temperature to balance mixing entropy and gravitational energy.
Area of Science:
- Physics
- Materials Science
- Statistical Mechanics
Background:
- Granular segregation is common in nature and industry.
- Existing models are often qualitative and lack a statistical mechanics basis.
Purpose of the Study:
- To investigate granular segregation using experimental methods.
- To develop a unified theoretical framework for granular segregation.
Main Methods:
- X-ray tomography was used to study particle mixtures.
- Experiments involved quasistatic cyclic shear of particles with differing densities.
Main Results:
- Steady-state height distributions were quantitatively characterized.
- A segregation temperature was identified, balancing entropy and energy.
- This temperature aligns with Edwards' compactivity.
Conclusions:
- Granular segregation under quasistatic conditions can be explained by thermodynamics.
- An effective granular thermodynamic framework with real energy terms is proposed.
- The Edwards statistical ensemble provides a basis for this framework.
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