This is what happens when layered materials are pushed to the brink

By studying the behavior of a deck of cards, and stacks of other materials, like steel and aluminum, scientists at Drexel University are proving the existence of a buckling phenomenon that happens inside layered materials when they are put under pressure. The discovery could shape the way researchers—from structural and mechanical engineers to geologists and seismologists—study the way things deform under pressure.

This phenomenon, described as "kinking non-linear elastic" behavior by the researchers in Drexel's Department of Materials Science and Engineering who first reported it in 2016, is best described as the separation and buckling of the internal layers of a material as they are compressed from the sides. Common examples are the way the cards in a deck of playing cards bend when you squeeze them from the edges without allowing the cards to separate, or how a ripple will sometimes form in a carpet if it is pushed from the edge.

In pressurized environments like this, whether at the card table or in the middle of tectonic plates, something has to give. Their theory explains exactly what that "give" looks like and how it happens. In their recent paper "Ripplocations: A Universal Deformation Mechanism in Solids," published in the journal Physical Review Materials, the researchers provide the first look at these internal waves, dubbed "ripplocations," that can be observed by the naked eye.