Calculations - Fast Soil Impact
This calculation shows the impact of a rocket in a sand box. The rocket is made of isotropic linear elastic material. The box contains sand which is modeled with Mohr-Coulomb elasto plasticity. At the border of the box displacements are suppressed. Mass inertia is taken into account in the analysis. Initially the rocket has a downward velocity of 100 m/s.
When you click on the picture below you will see a movie of the rocket penetrating the soil. It can be seen that at the top surface soil is pushed upwards, (the free surface line is being modeled). The rocket velocity is high, so the soil pushed away gets quite high velocity sidewards and due to inertia does not have time yet to refill the crater left behind by the rocket. This is opposed to slow soil penetration by an object where mass inertia is less important, so soil has the possibility to refill the crater left behind by the object.