Plastic instabilities in charged granular systems: Competition between elasticity and electrostatics

Area of Science:

• Physics
• Materials Science
• Condensed Matter Physics

Background:

• Electrostatic theory accounts for charges and dipolar excitations.
• Elasticity theory accounts for dipoles and quadrupolar plastic events.
• Charged amorphous granular systems present unique behaviors.

Purpose of the Study:

• To investigate plastic instabilities in charged amorphous granular systems.
• To examine the mechanical response to external strain and electric fields.
• To understand the interplay between elasticity and electrostatics.

Main Methods:

• A generic model for charged granular systems is proposed.
• Mechanical instabilities are analyzed using theoretical approaches.
• Saddle-node bifurcations are discussed in terms of Hessian matrix eigenvalues and eigenfunctions.

Main Results:

• The system exhibits moduli linking electric polarization and stress to strain and electric field.
• Theoretical expressions for these moduli are derived.
• Model predictions are compared with numerical simulation measurements.

Conclusions:

• The study provides a theoretical framework for understanding plastic instabilities in charged granular systems.
• The competition between elastic and electrostatic forces is elucidated.
• The findings contribute to the understanding of electromechanical coupling in granular materials.