Abstract:
Spacecraft encounter various impact phenomena in space, among which orbital
debris impacts are of most concern. These impacts occur at a wide range of
velocities. Impact velocities from a few hundreds m/s to one km/s are common in
geostationary orbit and even occur in low Earth orbit. However, these high
velocity impacts are not fully characterised. It’s required to study the
shielding performance in order to assess the spacecraft survivability in the
event of high velocity impacts. The paper is divided into two parts. Overall it
investigates the capability of hydrocodes to simulate high velocity impacts.
Particular interest is given to the post-penetration debris cloud
characterisation and the material failure mode identification. Three different
methods were used to simulate the impact of an aluminium sphere on a thin
aluminium plate. The first part, considers analyses performed using a finite
element model with element erosion and a discrete element method where the
problem is modelled with discrete finite elements with nodes tied with breakable
linkages. The second part of the paper considers the same problems with the
Smoothed Particle Hydrodynamics (SPH) method using the MCM solver developed at
Cranfield University. All three methods showed good agreement in terms of target
damage with the available experimental results. However, their performances are
different in terms of debris cloud and failure mode characterisation. As a large
number of elements are deleted, the element erosion method shows problems in the
petaling failure mode representation and doesn’t allow the post-penetration
debris cloud to be characterised. In order to be more reliable, the SPH method
needs improvements, in particular to avoid tensile instability. The discrete
element method allows good representation and identification of the failure
modes even if some improvements in the definition of the node linkage failure
criterion are requi
