A study on the injection of magnetic wires into cavities

Contas magnéticas se atraem, formando cadeias semelhantes às encontradas em fios. Essas cadeias podem ser estruturadas ou acondicionadas dentro de cavidades de formas diferentes daquelas observadas no caso de fios metálicos ou plásticos. Para entender em que condições essas cadeias podem ser estruturadas quando acondicionadas em cavidades, injetamos essas cadeias de fios magnéticos em uma célula Helle-Shaw inclinada e descobrimos que elas formam espontaneamente padrões autossimilares.
Ascânio Dias Araújo- Universidade Federal do Ceará em 27/04/2022

Abstract

Magnetic beads attract each other, forming chains similar to those found in wires. These chains can be structured or packaged inside cavities in different ways from those observed in the case of metallic or plastic wires. To understand under what condi- tions these chains might be structured when packed into cavities, we injected these chains of magnetic wires into a tilted Helle-Shaw cell and found that they spontaneously form self-similar patterns. Depending on the cell’s tilt angle, two completely different situa- tions arise; that is, above the angle of static friction the patterns resemble the stacking of a rope, and below they appear similar to a fortress seen from above. Furthermore, locally the first pattern forms a square network, while the second pattern exhibits tri- angular symmetry. For both patterns, the size distributions of closed areas follow power laws with different exponents. We characterize the morphological transition between the two patterns experimentally and numerically and explain the change in polarization as a competition between friction and gravity-induced buckling.

Local e Data

Tema: A study on the injection of magnetic wires into cavities
Palestrante: Ascânio Dias Araújo- Universidade Federal do Ceará
Data: 27/04/2022