Compaction of Quasi One-Dimensional Elastoplastic Materials

TL;DR

This paper investigates how friction, plasticity, and torsion influence the morphology and packing efficiency of crumpled wires in confined spaces, introducing a model to predict compaction outcomes based on material and process parameters.

Contribution

It presents a new self-avoiding random walk model that predicts the relationship between wire segment size and packing efficiency, accounting for material properties and injection conditions.

Findings

Friction, plasticity, and torsion increase disorder in crumpled structures.

Reducing wire thickness decreases maximum packing density in folding-dominated crumpling.

The model predicts universal dependence of injected wire length on segment size.

Abstract

Insight in the crumpling or compaction of one-dimensional objects is of great importance for understanding biopolymer packaging and designing innovative technological devices. By compacting various types of wires in rigid confinements and characterizing the morphology of the resulting crumpled structures, here we report how friction, plasticity, and torsion enhance disorder, leading to a transition from coiled to folded morphologies. In the latter case, where folding dominates the crumpling process, we find that reducing the relative wire thickness counter-intuitively causes the maximum packing density to decrease. The segment-size distribution gradually becomes more asymmetric during compaction, reflecting an increase of spatial correlations. We introduce a self-avoiding random walk model and verify that the cumulative injected wire length follows a universal dependence on segment size, allowing for the prediction of the efficiency of compaction as a function of material properties, container size, and injection force.