Hereby you will find a set of movies mentioned in the article "Granular physics in low-gravity environments using DEM" by Tancredi et al. (MNRAS, 2011).
A 3D box is constructed with elastic mesh walls. The box has a base of 6 × 6 m and a height of 150 m. A set of 12 × 12 m small balls of radius 0.25 m are glued to the floor. The big ball has a radius 0.75 m, and on top of it, there are 1000 small balls with radii ∼ 0.25 m.
The floor is displaced with a staircase function as described in the paper with different velocities.
We present movies for two set of simulations: a) under Earth's gravity (surface gravity g = 9.81 m/s²) and a floor's velocity (vfloor = 5 m/s), b) in a low-gravity environment (g = 0.0001 m/s²) and (vfloor = 0.05 m/s).
movie1.avi is a movie with all the spheres drawn and movie2.avi with the small spheres erased for the first simulation. The movies correspond to 100 seconds of simulated time and 50 shakes.
While movie3.avi and movie4.avi correspond to the second one. The movies correspond to 10000 seconds of simulated time and 667 shakes.
A 3D box similar to the previous one is created, with a 6 × 6 m base and a height of 150 m. The box is constructed with elastic mesh walls. On the floor we glue a set of 12 × 12 m small balls of radius 0.25 m and density ρ = 2000 kg/m³. There are 500 light balls with radii ∼ 0.25 m and density ρ = 500 kg/m³. On top of them, there are 500 heavy balls with similar radii and density ρ = 2000 kg/m³. At the beginning of the simulations the balls are placed sparsely, the light balls at the bottom and the heavy ones on top. They free fall and settle down before starting the floor shaking.
The floor is displaced with a staircase function in a similar way as in the previous set of simulations.
We present movies for two set of simulations: a) under Earth's gravity (surface gravity g = 9.81 m/s²) and a floor's velocity (vfloor = 3 m/s), b) in a low-gravity environment (g = 0.0001 m/s²) and (vfloor = 0.05 m/s).
movie5.avi is a movie of the first simulation, while movie6.avi corresponds to the second one. The movie5 corresponds to 1000 seconds of simulated time and 500 shakes, while the movie6 corresponds to 20000 seconds of simulated time and 1333 shakes.
Note that in these movies the camera moves with the floor, therefore it seems that the floor is always located in the same position, but it really is moving with the staircase function described above.
In movie5 the density segregation is not reached; while in movie6, most of the light particles move to the top and most of the heavy ones sink to the bottom.
We consider a km-size agglomerated body, formed by many small size boulders. We fill a sphere of radius 250 and 1000 m with ∼ 700,000 small spheres of a given size range (1-10 m-size boulders in the case of the small body, and 5-25 m-size boulders for the big body).
At a given point on the surface we select a certain number of particles of the body that are close to this place. Each particle has at the beginning of the simulation a velocity along the radial vector toward the centre. The location of the explosion is always at the surface and with angular coordinates (latitude = 45 deg, longitude = 45 deg). We run simulations with initial particle velocities of 100 m/s and 500 m/s.
In the movies we present snapshots showing the propagation of the wave into the interior. These are slices passing through the centre of the sphere, the explosion point and the poles. The particles are coloured using a colour bar that scales with the modulus of the velocity.
movie7.avi and movie8.avi correspond to the simulation with a body of radius 250 m, N = 783552 small particles and 140 particles with initial velocities of 100 m/s (case B-100) and 500 m/s (case B-500), respectively.
movie9.avi and movie10.avi correspond to the simulation with a body of radius 1000 m, N = 688443 small particles and 200 particles with velocities of 100 m/s (case D-100) and 500 m/s (case D-500). All the movies correspond to 10 seconds of simulated time.