Investigation of deformation mechanisms of staggered nanocomposites using molecular dynamics

• The deformation behaviour of staggered nanocomposites is studied.
• Stair-wise staggered model has high stiffness and strength, but low toughness.
• Rapid crack growth in overlap region causes this low toughness.
• Toughness could be enhanced by arresting interfacial crack in the overlap.

Biological materials with nanostructure of regularly or stair-wise staggered arrangements of hard platelets reinforced in a soft protein matrix have superior mechanical properties. Applications of these nanostructures to ceramic matrix composites could enhance their toughness. Using molecular dynamics simulations, mechanical behaviour of the bio-inspired nanocomposites is studied. Regularly staggered model shows better flow behaviour compared to stair-wise staggered model due to the symmetrical crack propagation along the interface. Though higher stiffness and strength are obtained for stair-wise staggered models, rapid crack propagation reduces the toughness. Arresting this crack propagation could lead to superior mechanical properties in stair-wise staggered models.