2020/03/27 by Shivam Mahajan, Michael Tennenbaum, Sudhir N. Pathak +9
Engineering · Mathematics · Physics and Astronomy · #Anomaly (physics) #Base (topology) #Composite material #Condensed matter physics #Constitutive equation #Cylinder #Finite element method #Geometry #Geotechnical Engineering and Soil Mechanics #Geotechnical and Geomechanical Engineering #Granular flow and fluidized beds #Granular material #Materials science #Mathematical analysis #Mathematics #Mechanics #Physics #Stress (linguistics) #Thermodynamics #cond-mat.soft
paper · pdf · doi:10.1103/physrevlett.124.128002
published as Phys. Rev. Lett. 124, 128002, 2020 · Supplementary material included; Editor suggestion; Featured in Physics
openalex publication_date 2020/03/27 · arxiv created 2020/05/29 · arxiv updated 2020/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
When grains are added to a cylinder, the weight at the bottom is smaller than the total weight of the column, which is partially supported by the lateral walls through frictional interactions with the grains. This is known as the Janssen effect. Via a combined experimental and numerical investigation, here we demonstrate a reverse Jansen effect whereby the fraction of the weight supported by the base overcomes one. We characterize the dependence of this phenomenon on the various control parameters involved, rationalize the physical process causing the emergence of the compressional frictional forces responsible for the anomaly, and introduce a model to reproduce our findings. Contrary to prior assumptions, our results demonstrate that the constitutive relation on a material element can depend on the applied stress.