A unified framework for non-brownian suspension flows and soft amorphous solids

Area of Science:

• Physics
• Materials Science
• Rheology

Background:

• Rheology of non-Brownian suspensions is understood in dilute regimes but not dense limits.
• Dense suspensions show collective particle motion, scaling properties, and approach a jamming transition.
• Elasticity of amorphous solids is governed by an unjamming transition, with scaling and diverging length scales.

Purpose of the Study:

• To establish a formal analogy between the rheology of dense flow and the elasticity of amorphous solids.
• To develop a new conceptual framework for relating microscopic structure to rheology in dense suspensions.
• To numerically compute normal modes and density of states for dense flow models.

Main Methods:

• Modeling dense flow near the jamming threshold.
• Establishing a formal analogy between flow rheology and network elasticity.
• Numerical computation of normal modes and density of states.

Main Results:

• A formal analogy is established between dense flow rheology and amorphous solid elasticity.
• Similarities found in the density of states for flow and amorphous solids near unjamming.
• A unique low-frequency mode (ω(min)) in flow density of states governs viscosity divergence.

Conclusions:

• The analogy provides a new framework to link microscopic structure to rheology in dense suspensions.
• The density of states in dense flow shares similarities with amorphous solids but exhibits a distinct low-frequency mode.
• This work offers insights into the physics of jamming and the rheology of dense materials.