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Size and density avalanche scaling near jamming.
Roberto Arévalo1, Massimo Pica Ciamarra
1CNR-SPIN, Dipartimento di Scienze Fisiche, Università di Napoli Federico II, Napoli, Italy. arevalo.robert@gmail.com.
Soft Matter
|March 18, 2014
Summary
Nonaffinity in jammed materials critically scales flow properties with proximity to jamming. This study introduces a new jamming exponent and hyperscaling, explaining friction coefficient dependence on volume fraction.
Area of Science:
- Physics of disordered materials
- Soft matter physics
- Computational materials science
Background:
- Current models of amorphous plasticity assume linear elasticity in local failure events.
- Flow properties of nonaffine systems (foams, emulsions, granular materials) near jamming remain debated.
- These systems exhibit fluctuating displacement fields during failure.
Purpose of the Study:
- To investigate the impact of nonaffinity on the flow properties of jammed materials.
- To rationalize the critical behavior observed in these systems.
- To establish relationships between nonaffinity, jamming, and macroscopic properties like friction.
Main Methods:
- Extensive numerical simulations of jammed materials.
- Analysis of displacement fields and flow properties.
- Development of theoretical frameworks including critical exponents and hyperscaling relations.
Main Results:
- Nonaffinity induces critical scaling of flow properties, dependent on the distance to the jamming point.
- A new universal jamming exponent governing this critical behavior was identified.
- Hyperscaling relationships were established, connecting microscopic nonaffinity to macroscopic properties.
- The volume fraction dependence of the friction coefficient was successfully described.
Conclusions:
- Nonaffinity plays a crucial role in the plasticity of jammed amorphous materials.
- The identified critical scaling and universal exponent provide a new framework for understanding jamming phenomena.
- This work offers a quantitative link between microscopic nonaffine dynamics and macroscopic friction.
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