Investigation of size, mass, and area-to-mass distributions in carbon-fiber-reinforced composite panels fragments from hypervelocity impacts

In the next decades, hypervelocity impacts between space objects are expected to increase in frequency due to the continuous growth of the orbital debris population and the deployment of large satellite constellations. Accurate characterization of fragment physical properties is therefore essential for the development and validation of breakup models and for the modelling of the debris environment, particularly in view of the increasing use of composite materials in spacecraft structures. In this work, fragments generated by four hypervelocity impacts on carbon-fiber-reinforced polymer (CFRP) panels are experimentally analysed with the aim of investigating size, mass, and area-to-mass (A/m) distributions. In these tests, aluminium spheres (1.9 mm and 2.9 mm diameter) impacted 4 mm thick CFRP plates at velocities between 3.5 km/s and 5.1 km/s, under conditions exceeding the ballistic limit.Fragments were individually catalogued through three-dimensional geometric measurements and mass determination, enabling the derivation of cumulative characteristic length distributions, mass-size correlations, and A/m distributions. Results show that fragment populations are strongly influenced by projectile diameter, with larger projectiles generating larger and more massive fragments, while smaller projectiles predominantly produce lighter debris. The mass-size scaling exhibits sub-quadratic behaviour, suggesting that fragment mass tends to increase more slowly than projected area with characteristic length, leading to increasing A/m values for larger fragments. Overall, the results provide a comprehensive three-dimensional experimental dataset for CFRP fragmentation and support the refinement of breakup models and debris environment simulations for composite spacecraft structures.