Crackling Noise during Slow Relaxations in Crumpled Sheets

Area of Science:

• Materials Science
• Physics
• Acoustics

Background:

• Ultrathin crumpled sheets exhibit complex mechanical behaviors, including slow relaxation and memory retention.
• Understanding the micromechanical origins of these phenomena is crucial for material design and application.

Purpose of the Study:

• To investigate the statistical properties of acoustic noise emitted by ultrathin crumpled sheets during mechanical loading.
• To elucidate the underlying micromechanical events responsible for logarithmic relaxation and memory effects.

Main Methods:

• Experimental measurement of acoustic noise emitted by crumpled sheets under load.
• Statistical analysis of the noise signal, focusing on event distribution and temporal characteristics.
• Application of log-Poisson distribution to characterize the observed micromechanical events.

Main Results:

• Logarithmic relaxation is characterized by a series of discrete, audible micromechanical events.
• The statistics of these events follow a log-Poisson distribution.
• This distribution provides a framework for understanding the slow relaxation and memory retention in these materials.

Conclusions:

• The findings constrain potential mechanisms governing the glasslike slow relaxation in crumpled sheets.
• The log-Poisson distribution offers a new perspective on the statistical nature of failure events in disordered materials.
• This study links acoustic emission to fundamental micromechanical processes in disordered systems.