Spiral patterns in the packing of flexible structures

• Published in: Physical review letters Vol. 97; no. 16; p. 166104
• Main Authors: Boué, L, Adda-Bedia, M, Boudaoud, A, Cassani, D, Couder, Y, Eddi, A, Trejo, M
• Format: Journal Article
• Language: English
• Published: United States 20-10-2006
• Subjects: Elasticity; Models, Theoretical; Molecular Conformation
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.97.166104

Spiral patterns are found to be a generic feature in close-packed elastic structures. We describe model experiments of compaction of quasi-1D sheets into quasi-2D containers that allow simultaneous quantitative measurements of mechanical forces and observation of folded configurations. Our theoretical approach shows how the interplay between elasticity and geometry leads to a succession of bifurcations responsible for the emergence of such patterns. Both experimental forces and shapes are also reproduced without any adjustable parameters.