Computational evaluation of metal foam orbital debris shielding

Aluminum honeycomb sandwich structures are widely used in aerospace applications, and are generally favored for their high specific strength and stiffness. However, experimental studies of their orbital debris shielding performance have shown an undesirable tendency to channel impact debris from a front face sheet impact, towards the back face sheet, inhibiting lateral debris dispersion. Hence published experimental research has evaluated the orbital debris shielding performance of aluminum foam sandwich panels, as a potential structural alternative. The limitations of light gas gun technology mean that experimental studies of this type can only investigate the lower half of the impact velocity regime of interest in low earth orbit applications. Recent research has conducted a series of 49 impact simulations, employing a hybrid-particle element method, in order to estimate the orbital debris shielding performance of aluminum foam sandwich panels for impact conditions which cannot be duplicated in the laboratory. The simulation results suggest that published scaling laws which extrapolate the experimental data base outside the testable range provide an accurate estimate of metal foam shielding performance over the full impact velocity range of interest for spacecraft operating in low earth orbit.