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Considerations on the relaxation time in shear-driven jamming
Lucas Hedström1, Peter Olsson1
1Department of Physics, <a href="https://ror.org/05kb8h459">Umeå University</a>, 901 87 Umeå, Sweden.
Physical Review. E
|July 18, 2024
Summary
We investigated the jamming transition in elastic particles under shear, focusing on relaxation time. Pressure correlations were found to be longer-lived than relaxation time correlations, impacting critical exponent determination.
Area of Science:
- Physics
- Materials Science
- Statistical Mechanics
Background:
- The jamming transition is a critical phenomenon observed in various disordered systems.
- Understanding the dynamics near the jamming point is crucial for predicting material properties.
Purpose of the Study:
- To investigate the jamming transition in a model of elastic particles under shear at zero temperature.
- To analyze the relaxation time (τ₁) and its correlation with pressure (p₁) during the jamming transition.
Main Methods:
- Two-step simulations: initial shearing followed by energy relaxation.
- Determining relaxation time (τ₁) from the exponential decay of energy.
- Analyzing correlations between τ₁, pressure (p₁), and shear variable (γ).
Main Results:
- Pressure correlations (p₁) were found to be longer-lived than relaxation time correlations (τ₁).
- Individual τ₁ is influenced by the starting configuration's pressure (p₁) and a random contribution dependent on relaxation path length.
- A specific shear variable, γτ, derived from τ₁ correlations, is identified as relevant for critical exponent determination.
Conclusions:
- The interplay between pressure and relaxation dynamics governs the jamming transition.
- The identified γτ provides a more accurate parameter for characterizing critical exponents in sheared granular systems.
- This study offers insights into the complex behavior of disordered materials near the jamming point.
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