Anomalous stress fluctuations in athermal two-dimensional amorphous solids

Area of Science:

• Physics
• Materials Science
• Computational Science

Background:

• Amorphous solids exhibit complex mechanical behaviors.
• Understanding stress distribution is crucial for material stability.
• Jamming transition in granular materials is a key area of research.

Purpose of the Study:

• To numerically investigate local stress distribution in 2D amorphous solids.
• To analyze stress fluctuations above the jamming transition.
• To compare numerical findings with theoretical predictions.

Main Methods:

• Numerical simulations of bidisperse frictionless disk packings.
• Analysis of the Fourier transform of local stress.
• Study of inherent states of quenched Lennard-Jones liquids.

Main Results:

• Evidence of algebraically increasing stress fluctuations at small wave numbers.
• Demonstration of a lack of self-averaging of stress on large length scales.
• Identification of a stress fluctuation crossover length scale (ℓ₀) that shows weak dependence on packing fraction.

Conclusions:

• Numerical results contradict recent theoretical predictions for stress fluctuations.
• Increasing stress fluctuations may be a general characteristic of 2D amorphous solids.
• The findings have implications for the mechanical properties and stability of disordered materials.