Persistent homology analysis of craze formation

Area of Science:

• Materials Science
• Polymer Physics
• Computational Materials Science

Background:

• Crazing is a critical failure mechanism in glassy polymers, involving the formation and growth of voids.
• Understanding nanovoid behavior during crazing is essential for predicting polymer mechanical properties.
• Previous studies have lacked detailed insights into the dynamic evolution of nanovoids at the nanoscale.

Purpose of the Study:

• To investigate the behavior and coalescence of nanovoids during the polymer crazing process.
• To apply persistent homology as a novel analytical tool for studying nanovoid dynamics.
• To elucidate the relationship between nanovoid percolation and the yielding behavior of glassy polymers.

Main Methods:

• Coarse-grained molecular dynamics simulations were employed to model the uniaxial deformation of amorphous polymers.
• Persistent homology analysis was utilized to analyze the topological changes in the void structure.
• The simulation data captured the evolution of nanovoids under stress.

Main Results:

• Persistent homology effectively identified and tracked the coalescence of nanovoids during craze formation.
• The analysis revealed distinct topological signatures associated with void merging events.
• Simulation results demonstrated a clear correlation between nanovoid percolation and the onset of polymer yielding.

Conclusions:

• The study establishes persistent homology as a powerful method for analyzing complex void evolution in polymers.
• The findings support the hypothesis that polymer yielding is fundamentally a percolation phenomenon driven by nanovoids.
• This work provides a new perspective on polymer failure mechanisms at the nanoscale.