Fragmentation as an aggregation process

Abstract

International audienceno abstrac

Fragmentation as an aggregation process: the role of defects

“…Building on our previous work on the fragmentation of a ring of interacting spherical magnets [17], we study here a ring made of water absorbent polymer spheres linked by capillary bridges. The spheres or 'water beads' are made of a polyacrylamide hydrogel (http:// autourdelafleur.fr (2015)).…”

“…It also yields a relation between the final mean fragment size n ∞ and the Weber number. In the mean, the divergence velocity is U(n ∞ , n ∞ ) = n ∞ U and the condition β(n ∞ , n ∞ ) = 1 yields a mean final fragment size [17] n ∞ = 2 We …”

“…Surface energy is also a core element of numerical simulations based on a cohesive-law fracture model that have been used to address the fragmentation of rings [25][26][27] or brittle objects of more complex geometries [28]. The detailed construction of the fragment size distribution from an expanded ring of discrete particles linked by a cohesive force decreasing as a power law with distance has been developed in an accompanying paper [17]. By watching the process in real time, it was found that the distribution evolves in a self-similar manner through an 'inverse cascade' of aggregations from small to large fragment sizes by the progressive closing of cohesive links until the exhaustion of the dilatational kinetic energy.…”

“…The Mott ring experiment [11,15,16] is a remarkable framework to elaborate our understanding of fragmentation [17]. A ring made of a cohesive material is initially communicated a radial speed, leading to a uniform tensile hoop stress along the ring.…”

“…Using necklaces of cohesive magnetized spheres suddenly expanded, we have shown that the fragmentation of this one-dimensional material results from an inverse aggregation cascade (Vledouts et al 2015 Proc. R. Soc.…”