A coupled SPH–FEM strategy for hypervelocity impact analysis with emphasis on shock-wave transmission in Whipple shields

• SPH–FEM coupling formulated for reliable stress-wave propagation. • Hybrid interface zone improves energy transfer across domains. • Validated using literature and new Airbus Whipple shield tests. • Secondary cloud damage potential quantified via velocity mapping. • Method applicable to spacecraft structural integrity assessment. The population of orbital debris in Low Earth Orbit (LEO) continues to increase steadily. This situation is driven by a combination of human space activities and collisions between objects in orbit, which are becoming increasingly unavoidable and pose a significant threat to space missions. This work addresses debris–spacecraft collision phenomena by first investigating the hypervelocity impact of a projectile on a single plate. A coupled smoothed particle hydrodynamics (SPH) and finite element method (FEM) numerical framework, implemented in the commercial code LS-DYNA®, is developed to simulate this process and correlated with publicly available hypervelocity impact experimental data. The methodology is subsequently optimised and extended to a more complex configuration, namely a Whipple shield, which is more representative of realistic spacecraft shielding concepts against debris impacts. Validation is performed using an experimental dataset provided by Airbus Defence and Space. Unlike conventional SPH/FEM coupling approaches that are primarily used to improve local damage modelling near the impact zone, the proposed framework is deliberately formulated to enable consistent propagation of shock waves and stress fields into the surrounding finite element domain. This enables the method to be employed not only for accurate fragmentation modelling, but as a physics-driven approach for analysing energy transport and shock propagation within spacecraft structures following hypervelocity impacts. The developed methodology enhances insight into spacecraft structural behaviour under hypervelocity debris impacts and supports its application in the design and optimisation of future spacecraft shielding solutions.