On the elastoplastic behavior in collisional compression of spherical dust aggregates

TL;DR

This study uses numerical simulations and a theoretical elastoplastic sphere model to analyze how dust aggregates deform during collisions, revealing size and velocity effects on compression and advancing understanding of dust growth in space.

Contribution

It introduces a combined numerical and theoretical approach to model elastoplastic deformation of dust aggregates during collisions, highlighting size and velocity dependencies.

Findings

Maximum compression length scales with aggregate radius.

Collision velocity increases maximum compression length.

The elastoplastic sphere model accurately predicts observed behaviors.

Abstract

Aggregates consisting of submicron-sized cohesive dust grains are ubiquitous, and understanding the collisional behavior of dust aggregates is essential. It is known that low-speed collisions of dust aggregates result in either sticking or bouncing, and local and permanent compaction occurs near the contact area upon collision. In this study, we perform numerical simulations of collisions between two aggregates and investigate their compressive behavior. We find that the maximum compression length is proportional to the radius of aggregates and increases with the collision velocity. We also reveal that a theoretical model of contact between two elastoplastic spheres successfully reproduces the size- and velocity-dependence of the maximum compression length observed in our numerical simulations. Our findings on the plastic deformation of aggregates during collisional compression provide a clue to understanding the collisional growth process of aggregates.