Was da Vinci wrong? Experts show friction and fracture are related, with implications for earthquakes

Jul 07, 2014

Overturning conventional wisdom stretching all the way to Leonardo da Vinci, new Hebrew University of Jerusalem research shows that how things break (fracture) and how things slide (friction) are closely interrelated. The breakthrough study marks an important advance in understanding friction and fracture, with implications for describing the mechanics that drive earthquakes.

Over 500 years ago, da Vinci described how rough blocks slide over one another, providing the basis for our understanding of to this day. The phenomenon of fracture was always considered to be something totally different.

But new research by Prof. Jay Fineberg and his graduate student Ilya Svetlizky, at the Hebrew University's Racah Institute of Physics, has demonstrated that these two seemingly disparate processes of fracture and friction are actually intimately intertwined.

Appearing in the journal Nature, their findings create a new paradigm that's very different from the da Vinci version, and, according to the researchers, give us a new understanding of how earthquakes actually occur.

Fineberg and Svetlizky produced "laboratory earthquakes" showing that the friction caused by the sliding of two contacting blocks can only occur when the connections between the surfaces are first ruptured (that is, fractured or broken) in an orderly, "organized" process that takes place at nearly the speed of sound.

How does this happen? Before any motion can occur, the blocks are connected by interlocking rough contacts that define their interface. In order for motion to occur, these connections have to be broken. This physical process of breaking is called a fracture process. This process is described by the theory of crack propagation, say the researchers, meaning that the stresses (or forces) that exist at the front edge of a crack become highly magnified, even if the overall forces being applied are initially quite small.

"The insights gained from our study provide a for understanding friction and give us a new, fundamental description of the mechanics and behavior that drive earthquakes, the sliding of two tectonic blocks within natural faults," says Fineberg. "In this way, we can now understand important processes that are generally hidden kilometers beneath the earth's surface."

Explore further: Engineers develop new methods to speed up simulations in computational grand challenge

More information: "Classical shear cracks drive the onset of dry frictional motion." Ilya Svetlizky, Jay Fineberg. Nature 509, 205–208 (08 May 2014) DOI: 10.1038/nature13202. Received 18 November 2013 Accepted 25 February 2014 Published online 07 May 2014

add to favorites email to friend print save as pdf

Related Stories

Friction research casts doubt on fundamental physics law

Oct 11, 2010

(PhysOrg.com) -- New research on frictional slipping has revealed that some of the basic assumptions of introductory physics do not hold at small scales. The findings may be useful in the study of earthquakes.

Finnish researchers find explanation for sliding friction

May 29, 2012

Friction is a key phenomenon in applied physics, whose origin has been studied for centuries. Until now, it has been understood that mechanical wear-resistance and fluid lubrication affect friction, but the fundamental origin ...

In static friction, chemistry is key to stronger bonds

Nov 07, 2012

(Phys.org)—Inspired by phenomena common to both earthquakes and atomic force microscopy, University of Wisconsin–Madison materials engineers have learned that chemical reactions between two silicon dioxide surfaces cause ...

Recommended for you

Fluctuation X-ray scattering

16 hours ago

In biology, materials science and the energy sciences, structural information provides important insights into the understanding of matter. The link between a structure and its properties can suggest new ...

Hydrodynamics approaches to granular matter

18 hours ago

Sand, rocks, grains, salt or sugar are what physicists call granular media. A better understanding of granular media is important - particularly when mixed with water and air, as it forms the foundations of houses and off-shore ...

Behind the dogmas of good old hydrodynamics

20 hours ago

A new theory, which gives insights into the transport of liquid flowing along the surface under an applied electric field, was developed by a group of Russian scientists lead by Olga Vinogradova who is a ...

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.