Abstract
Granular asteroids are naturally occurring gravitational aggregates (rubble piles) bound together by gravitational forces. For this reason, it is reasonable to use the theoretical concepts and numerical tools developed for granular media to study them. In this paper, we extend the field of applicability of the Contact Dynamic (CD) method, a class of non smooth discrete element approach, for the simulation of three dimensional granular asteroids. The CD method is particularly relevant to address the study of dense granular assemblies of a large number of particles of complex shape and broad particles size distribution, since it does not introduces numerical artefacts due to contact stiffness. We describe how the open source software LMGC90, interfaced with an external library for the calculation of self-gravity, is used to model the accretion process of spherical and irregular polyhedral particles.
Highlights
During the last two decades, research about asteroids in general and small asteroids in particular has increased dramatically
The Contact Dynamics (CD) method involves an e cient iterative algorithm based on a nonlinear GaussSeidel scheme for solving the equations of dynamics of the particles, satisfying at the same time the complementarity relations for contact forces and particle velocities at the end of each time step[12, 13]
We have presented the general ingredients of the Contact Dynamics (CD) method for the simulation of gravitational aggregates, and its implementation in the open-source code LMGC90
Summary
During the last two decades, research about asteroids in general and small asteroids in particular has increased dramatically. One common objective in all these missions is the return of a sample of the particles on their surfaces for analysis. The use of numerical methods to simulate the interaction of the spacecrafts with the asteroid surfaces has been an important part of the research [6,7,8]. In Non Smooth approaches, which main method is the Contact Dynamics (CD) introduced in the 90s by J.-J. Moreau [10, 11], the interactions between particles are described by non-smooth contact laws instead of force laws. We use the CD method to model the accretion of spherical and polyhedral particles under selfgravity. The general ingredients of the CD method together with specific ingredients needed for modeling granular asteroids (polyhedral shape and self-gravity implementation) are first introduced. The main results of accretion simulations are discussed and some perspectives are given regarding forthcoming research
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
