Ultradelayed material failure via shear banding after straining an amorphous material.

Area of Science:

• Materials Science
• Physics
• Rheology

Background:

• Amorphous materials can exhibit complex failure behaviors.
• Understanding delayed failure mechanisms is crucial for material performance.

Purpose of the Study:

• To predict and explain catastrophic material failure with a significant delay after deformation.
• To identify the underlying physics of ultra-delayed shear banding instability.

Main Methods:

• Simulations of mesoscopic soft glassy rheology model (1D).
• Simulations of mesoscopic elastoplastic models (1D and 2D).
• Simulations of a continuum fluidity model (1D).

Main Results:

• Demonstrated ultra-delayed shear banding instability leading to sudden strain localization and stress drop.
• Delay time increases with decreasing strain amplitude, decreasing temperature, and increased annealing.
• Observed consistent physics across three distinct constitutive models.

Conclusions:

• The predicted failure mechanism may be generic across amorphous materials.
• This counter-intuitive phenomenon has implications for material processing and performance.
• The findings are experimentally testable and relevant for particle simulations.