USING A HIERARCHY OF POROSITY TO IMPROVE THE FRACTURE TOUGHNESS OF METAMATERIALS
Kaitlynn FitzgeraldDogwood A
Mechanical metamaterials have been quickly growing in popularity based on their lightweight, multifunctional properties. One of the factors limiting their widespread adoption in weight baring applications, however, is their poor fracture toughness compared to bulk materials. Arrestor planes have been added to gyroid surface metamaterials and solid beams to manipulate the path of a propagating crack and improve the fracture toughness. The arrestor planes used a hierarchy of porosity interacting with the features inherent in the gyroid topology to direct propagating cracks into natural features that served to arrest the crack. This methodology was tested in both brittle polymer and stainless steel with toughening ranging from 22% to 300% depending on material.