Rearrangements and dilatancy for sheared dense materials

Area of Science:

• Materials Science
• Rheology
• Solid Mechanics

Background:

• Understanding the mechanical behavior of dense materials under stress is crucial for various engineering applications.
• Existing models may not fully capture the complex rearrangements occurring at the microstructural level.

Purpose of the Study:

• To propose novel constitutive equations for dense materials.
• To identify and model free-volume activated rearrangements responsible for material response.

Main Methods:

• Development of constitutive equations based on identified rearrangement mechanisms.
• Simulation of material behavior in a stress-strain test for amorphous solids.
• Analysis of lubricant behavior in a tribology test.

Main Results:

• The proposed equations successfully model dense materials.
• Observed phenomena include strain softening, shear thinning, and stick-slip motion.
• The model links macroscopic behavior to microscopic free-volume dynamics.

Conclusions:

• The constitutive equations provide a unified framework for understanding dense material behavior.
• Free-volume activated rearrangements are key to explaining observed rheological phenomena.
• The model has implications for predicting material performance in diverse applications.