A continuous damage random thresholds model for simulating the fracture behavior of nacre

Area of Science:

• Materials Science
• Biomimetics
• Computational Mechanics

Background:

• Nacre exhibits exceptional mechanical properties, including high toughness and strength.
• Its unique brick-and-mortar microarchitecture is key to its performance.
• Understanding nacre's fracture mechanisms is crucial for designing advanced materials.

Purpose of the Study:

• To investigate the fracture properties of nacre using a computational model.
• To elucidate the relationship between nacre's microarchitecture and its mechanical behavior.
• To validate a discrete lattice model against experimental data.

Main Methods:

• A discrete lattice model was developed, simulating nacre's brick-and-mortar structure.
• The model incorporates continuous damage mechanics and random threshold fuse network principles.
• Mechanical behavior was governed by the damage evolution of organic matrices and mineral bridges.

Main Results:

• The discrete lattice model accurately reproduced experimental results for nacre's stiffness, tensile strength, and work of fracture.
• Nacre's superior toughness is attributed to the ductility of the organic matrix.
• Fracture strength is linked to the ordered architecture and platelet overlap.

Conclusions:

• The study validates a discrete lattice model for simulating nacre's fracture.
• Organic matrix ductility and brick-and-mortar architecture are critical for nacre's toughness and strength.
• This model provides insights for biomimetic material design.