Onset of localization in heterogeneous interfacial failure

Area of Science:

• Materials Science
• Solid Mechanics
• Computational Physics

Background:

• Understanding interface failure is crucial for designing robust composite materials and structures.
• Previous models suggested phase transitions in failure mechanisms, which require further investigation.

Purpose of the Study:

• To numerically investigate the failure process of an interface between two elastic materials under load.
• To analyze the role of spatial correlations and localization in interface failure.
• To clarify the nature of the transition between different failure regimes.

Main Methods:

• Utilized a fiber bundle model numerically linked to an elastic half-space.
• Simulated interface failure under applied load.
• Varied the elastic constant of the half-space to observe changes in failure behavior.

Main Results:

• The failure process aligns with the equal load sharing fiber bundle model, lacking spatial correlations until localization occurs.
• Localization onset relative to the critical load depends on the elastic constant of the half-space.
• A crossover, not a phase transition, exists between localized and non-localized failure modes.
• A finite fraction of fiber failures precedes the critical load, even in extreme localization.
• The critical load remains finite for all elastic constants in an infinite system.

Conclusions:

• The study reveals a crossover in interface failure mechanisms rather than a phase transition.
• Numerical simulations demonstrate that localization plays a significant role, but initial fiber failure is always substantial.
• The findings provide a more nuanced understanding of material interface failure under load.