A jamming plane of sphere packings.

Research Highlight

Seeing the bigger picture of jamming

© MirageC/Moment/Getty Images

© MirageC/Moment/Getty Images

Spheres randomly thrown together can jam over a wider range of conditions than previously thought, a new description of jamming reveals.

A wide range of materials exhibit the phenomenon of jamming in which their constituent particles become clogged together so that they are no longer free to flow. Randomly arranged spheres have been observed to jam when they reach a density of about 64%.

Now, by performing computer simulations of jamming of randomly assorted spheres, a researcher at Osaka University and a collaborator have shown that jamming can occur at lower densities than this, depending on factors such as the amount of shear and strain.

They have developed a more unified framework for jamming that covers jamming produced by both compression and shear mechanisms. The common factor is that the onset of jamming coincides with the formation of structures that are barely stable.

Supported content

  1. PNAS 118, e2021794118 (2021). doi: 10.1073/pnas.2021794118
Institutions Share
Osaka University, Japan 0.67
Institute of Theoretical Physics (ITP), CAS, China 0.17
University of Chinese Academy of Sciences (UCAS), China 0.17