Deformation and Toughening Mechanisms in Nacreous Structures

Nacre’s outstanding fracture properties has fascinated materials scientists for the past three decades. The inner layer of abalone shell which is made up 95% of aragonite platelets and 5% proteins possess a fracture toughness that is three orders of magnitude higher than pure aragonite. This article presents a summary of our work during the past decade on understating the deformation and toughening mechanisms in nacre and its implications on the design of bioinspired nacreous structures. A detailed shear lags model is presented that can be extensively used for design of architected multilayered materials. Additionally, this article shows the importance of mineral bridges, that are present in the structure of nacre, and employed in cement composites.