Flaw tolerance promoted by dissipative deformation mechanisms between material building blocks

Abstract

Novel high-performance composite materials often draw inspiration from natural materials such as bone or mollusc shells. A prime feature of such composites is that they are, like their natural counterparts, quasibrittle. They are tolerant to material flaws up to a certain characteristic flaw-tolerant size scale, exhibiting high strength and toughness, but start to behave in a brittle manner when sufficiently large flaws are present. Here, we establish that better flaw tolerance can be achieved by maximizing fracture toughness relative to the maximum elastic energy available in the material, and we demonstrate this concept with simple two-dimensional coarse-grained simulations where the transition from brittle to quasibrittle behaviour is examined.

Keywords:

• flaw tolerance
• coarse-grained simulation
• quasibrittleness
• dissipation
• fracture toughness

Acknowledgements

The authors acknowledge funding from Fulbright Center Finland and The Federation of Finnish Technology Industries. Further support was provided by AFOSR and NSF.