Controlling crackling dynamics by triggering low-intensity avalanches

Area of Science:

• Physics
• Materials Science
• Complex Systems

Background:

• Crackling dynamics describe systems with abrupt changes, like fracture.
• Heterogeneous solids exhibit complex crack propagation behavior.
• Controlling extreme events in these systems is crucial for safety and predictability.

Purpose of the Study:

• To investigate the impact of periodic excitations on crackling dynamics in brittle fracture.
• To determine how excitation parameters influence avalanche statistics and event magnitudes.
• To identify optimal control strategies for suppressing extreme crack events.

Main Methods:

• Applying small, spatially localized, and periodic excitations to a slowly driven brittle crack.
• Analyzing avalanche statistics under different excitation manners (random vs. loaded point).
• Systematically varying excitation amplitude, spatial extent, and frequency.

Main Results:

• Excitations significantly alter avalanche statistics and limit the magnitude of largest events.
• Excitation effectiveness is independent of the crack front's loading state during application.
• Excitation efficiency is governed by injected power per unit front length, with an optimal value for maximum suppression of extreme avalanches.

Conclusions:

• Periodic excitations offer a novel method to control extreme events in crackling dynamics.
• The findings are applicable to fracture mechanics and other universality classes like wetting and magnetic systems.
• Optimal control is achieved by tuning injected power per unit front length.