Shattered glass: New theory explains how things break

May 01, 2013 by Anne Ju
Shattered glass: New theory explains how things break
Abrupt fracture happens in large objects at low disorder (glass), while an accumulation of distributed damage results in fracture in small objects at high disorder (seashells). A new theory explains the properties of the distributed precursor damage, and the emergence of abrupt fracture at low disorder or at long length scales. Image A, courtesy of R.O. Ritchie's group at Lawrence Berkeley National Laboratory, shows abrupt fracture at long scales in human bone, and Image B shows distributed damage in a composite material.

(Phys.org) —Shattering a glass is a completely different experience than breaking a seashell, and Cornell physicists offer a notion – at the microscale – to explain why.

A new, unified theory of fracture is detailed in a Physical Review Letters paper published April 29, with senior author James P. Sethna, professor of physics, graduate student Ashivni Shekhawat, and Stefano Zapperi of CNR Milan. The paper was selected by the journal as an "Editor's Choice."

Glass, say the researchers, is a "clean" system that breaks abruptly in one nucleated event when the weakest spot fails. But materials like bones, seashells and composites, called disordered media, can have multiple microcracks that form and grow before the final failure. The researchers provided a universal scaling theory for this distributed damage that explains fundamentally why these types of materials break so differently.

Previous theories had held that a phase transition separates abrupt fracture in clean systems like glass, and fracture with substantial distributed damage, like bone.

The Cornell scientists instead offer the theory of a smoother crossover between abrupt fracture at low disorder (glass), and accumulation of distributed damage at high disorder (seashell), using universal scaling functions. Bones, seashells and modern are tougher than glass because of this phenomenon of distributed damage. The researchers show how disorder leads to damage for small systems, and catastrophic crack at longer length scales.

The paper is titled "From Damage Percolation to Crack Nucleation Through Finite Size Criticality." The work was supported by the Department of Energy.

Explore further: Scaling up armor systems

More information: prl.aps.org/abstract/PRL/v110/i18/e185505

Related Stories

New glass tops steel in strength and toughness

Jan 10, 2011

(PhysOrg.com) -- Glass stronger and tougher than steel? A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of any known material, has been developed and tested ...

Physicists study probability of structural failure

Feb 28, 2012

It doesn't happen often, but structures like bridges, airplanes and buildings do fail, sometimes catastrophically. What are the odds, and how can it be prevented? Cornell physicists are using computer modeling ...

Physicists unlock the mysteries of crack formation

Mar 05, 2010

(PhysOrg.com) -- In research published in the March 4 issue of the journal Nature, Northeastern University physicists have pioneered the development of large-scale computer simulations to assess how cracks ...

Recommended for you

Galaxy dust findings confound view of early Universe

12 hours ago

What was the Universe like at the beginning of time? How did the Universe come to be the way it is today?—big questions and huge attention paid when scientists attempt answers. So was the early-universe ...

Evidence mounts for quantum criticality theory

Jan 30, 2015

A new study by a team of physicists at Rice University, Zhejiang University, Los Alamos National Laboratory, Florida State University and the Max Planck Institute adds to the growing body of evidence supporting ...

Scaling up armor systems

Jan 30, 2015

Dermal modification is a significant part of evolution, says Ranajay Ghosh, an associate research scientist in the College of Engineering. Almost every organism has something on its skin that provides important ...

Seeking cracks in the Standard Model

Jan 30, 2015

In particle physics, it's our business to understand structure. I work on the Large Hadron Collider (LHC) and this machine lets us see and study the smallest structure of all; unimaginably tiny fundamental partic ...

The first optically synchronised free-electron laser

Jan 30, 2015

Scientists at DESY have developed and implemented an optical synchronisation system for the soft X-ray free-electron laser FLASH, achieving facility-wide synchronisation with femtosecond precision. The performance ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.