Numerical Performance Evaluation of FGM Spacecraft Panels under Hypervelocity Debris Impact

Orbital space debris in LEO poses a systemic integrity concern to satellites’ structure and requires higher levels of passive shielding beyond traditional Whipple shield configurations. This paper presents an investigation of the impact tolerance of Functionally Graded Material sandwich panels subjected to hypervelocity impact phenomena under a non-linear computational framework.
A comparison of an Al7075-T6 structure and an alumina-nickel P-FGM (Power-Law Functionally Graded Material) structure is performed to optimize hardness and energy-absorbing properties of metallic and ceramic constituents of composite structures. The structural response is analyzed for 1-1-1, 1-2-1, and 2-2-1 configurations of FGM panel. A high-fidelity computational framework of a lagrangian SPH-based coupled solver is implemented to simulate impact phenomena of a spherical steel projectile traveling at a nominal LEO impact velocity of 5 km/s.
Results demonstrate that while monolithic aluminum panels suffer total perforation and catastrophic fragmentation, while the FGM architecture effectively arrests the debris cloud and localizes kinetic energy dissipation. By localizing kinetic energy dissipation, the P-FGM panels minimize the propagation of high-frequency shockwaves to internal bus electronics. Parametric studies reveal that the volume fraction index and core-to-facesheet thickness ratios are critical determinants of ballistic limit velocity. This research provides a design roadmap for integrating FGM shielding into SmallSat primary structures, offering superior protection with a lower mass-fraction compared to conventional monolithic alloys.