Toughening mechanisms in bioinspired multilayered materials

Area of Science:

• Materials Science
• Biomimetics
• Mechanics of Materials

Background:

• Biological multilayered materials exhibit exceptional mechanical properties due to nanoscale structural features.
• Abalone nacre serves as a model for understanding these properties, with its organic matrix, pillars, and aragonite platelet roughness being key contributors.

Purpose of the Study:

• To explore the mechanical behavior and toughening mechanisms of abalone nacre-inspired multilayered materials.
• To develop and validate a micromechanical model for simulating deformation and toughening in these materials.

Main Methods:

• Proposed a micromechanical model incorporating nanoscale pillars with near theoretical strength.
• Assumed pillars and asperities confine the organic matrix, enhancing its stiffness.
• Validated model results against experimental data for abalone nacre.

Main Results:

• Demonstrated synergistic effects of aragonite platelets, pillars, and organic matrix on nacre stiffness.
• Highlighted significant contributions of pillars to the overall mechanical performance.
• Identified roughness-induced interactions as crucial for strength and toughness.

Conclusions:

• The proposed model accurately simulates abalone nacre's mechanical deformation and toughening.
• Nanoscale pillars and roughness-induced interactions are critical for nacre's strength, toughness, and nonlinear behavior.
• Tensile toughness is directly influenced by the interplay of microstructural components.