Synopsis: Cracking the case on fracture

A new model explores how the spacing between defects in materials is key to controlling their resistance to fracture.

Designers and engineers need to be constantly aware of failure modes in materials. Material breakdown often involves fracture, and the ways in which cracks propagate must be understood to prevent their initiation and ensure safety margins. Many material engineering studies are carried out within a model of continuum plasticity, yet such models often lack sufficient microscopic detail to account for crack propagation and fracture resistance. Writing in Physical Review Letters, Srinath Chakravarthy and William Curtin of Brown University in the US report computer simulations showing more clearly what processes influence fracture in plastic deformation, and on what length scales.

The authors model plastic deformation as the movement of discrete dislocations along slip planes. Specifically, a set of “obstacles” arrayed with some selected spacing restricts the movement of dislocations and modifies the plasticity. They then examine fracture by including an initial crack in the material and observing it propagate as a function of material cohesive strength, fracture energy, and obstacle spacing. Chakravarty and Curtin find that it is the obstacle spacing length scale that most strongly affects fracture toughness. Moreover, they propose that their model could serve as a more general simulation environment for fracture studies in various materials. –David Voss


Announcements

More Announcements »

Subject Areas

Materials Science

Previous Synopsis

Quantum Information

A spin on graphene

Read More »

Next Synopsis

Cosmology

Cosmic question

Read More »

Related Articles

Focus: Complex Crystals Form from Heterogeneous Particles
Materials Science

Focus: Complex Crystals Form from Heterogeneous Particles

A suspension containing particles with wide-ranging diameters can crystallize into multiple ordered structures. Read More »

Synopsis: Glassy Fingerprints
Condensed Matter Physics

Synopsis: Glassy Fingerprints

The local structure of glasses and other disordered materials could be extracted from diffraction patterns, according to a proposal for a new technique. Read More »

Synopsis: Electron–Phonon Affair Comes to Light
Condensed Matter Physics

Synopsis: Electron–Phonon Affair Comes to Light

Photoelectron spectroscopy reveals the details of the interaction between electronic and vibrational excitations in a molecular material. Read More »

More Articles