Residual strength and damage quantification for hypervelocity impact of CFRP truss members

Space assets require materials that can endure extreme environments while maintaining a high strength-to-weight ratio, a critical factor due to the high costs of space flight. Increasingly, micrometeoroid and orbital debris (MMOD) pose significant risks to these assets. Carbon fiber reinforced polymers (CFRPs) offer an improved balance of mechanical and physical properties for MMOD shielding and structural components, as they can be customized to specific applications. Assessing the impact of MMOD on CFRP truss members is essential to evaluate their viability for large-scale space structures in future missions. This study focuses on identifying and quantifying the sub-surface damage from MMOD impacts on circular CFRP truss members and measuring the residual strength of individual truss members post-impact. Using high-speed imaging and X-ray computed tomography (XCT), this study quantified the extent of sub-surface delamination and residual strength loss in CFRP truss members impacted by hypervelocity projectiles, while compression after impact (CAI) tests were employed to measure the mechanical degradation caused by such impacts. The results indicate that sub-surface delamination, rather than the size of the hypervelocity impact entry hole, has the strongest correlation to the reduction in strength of the damaged composite truss members.