Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009dps....41.2711s&link_type=abstract
American Astronomical Society, DPS meeting #41, #27.11
Astronomy and Astrophysics
Astronomy
Scientific paper
Thermal (YORP) spin-up of cohesionless gravitational aggregates (rubble-piles) has been shown, through recent numerical simulations, to spawn binary asteroid configurations that closely match the observed properties of small binaries, such as near-Earth asteroid 1999 KW4. However, the existence of small asteroids rotating at rates faster than their gravitational break-up limits motivates the inclusion of modest cohesion in models of gravitational aggregates. We have begun to explore the effect of weak cohesion on gravitational aggregate dynamics in our numerical simulations.
Our model features the use of spring-like forces between neighboring particles. This force acts in resistance to deviation from the initial displacement (strain) between two neighboring particles. A restoring force between them is generated and increases as the magnitude of this strain increases, until a maximum strain is reached, at which point the "spring” breaks and the cohesion between the particles vanishes. Just recently, we added the capability to allow for variation in strength between different pairs of neighboring particles within the same simulation (we use a Gaussian distribution of strength, but this is easily generalized to any desired network of initial flaws/fractures).
In order to explore the bulk properties that describe materials created by an agglomeration of particles that exhibit this type of cohesive force, a series of simulated stress tests were designed and carried out; we present the results of these tests and compare them to ones involving real materials and to solutions of relevant analytical models. We also report on current simulations that explore the reconfiguration response to imposed rotational stress for a range of initial asteroid parameters. This work was supported by the National Aeronautics and Space Administration under Grant No. NNX08AM39G issued through the Office of Space Science and by the National Science Foundation under Grant No. AST0708110.
Michel Pascal
Richardson Chris D.
Schwartz Stephen R.
Walsh Kevin J.
No associations
LandOfFree
Modeling Cohesion in Gravitational Aggregates with Variable Bond Strengths does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Modeling Cohesion in Gravitational Aggregates with Variable Bond Strengths, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Modeling Cohesion in Gravitational Aggregates with Variable Bond Strengths will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1332853