Resilient carbon fiber network materials under cyclic compression

The thermal protection system (TPS) for the reusable reentry spacecraft is designed to protect the structure from extremely high temperatures for many times launch and reentry. To meet the requirements, the TPS requires excellent thermal insulation performance, mechanical properties and strong ability to recover deformation with a minimum lifetime of dozens of missions. In this paper, we fabricated carbon-bonded carbon fiber composites (CBCFs) with a 3D network structure, and the deformation mechanisms under cyclic compression were systematically analyzed. This work demonstrated the excellent resilience behavior of CBCFs with cyclic loading. Quantitative numerical modeling and experimental tests revealed that the CBCFs could completely recover the deformation with strain up to 40% and maintained structural integrity with low energy dissipation (<∼0.3). The resilient behavior in the out-of-plane direction was mainly attributed to elastic deformation of fibers and contact of neighboring fibers, and most of the energy was dissipated by the sliding between fibers. The in-plane deformation of CBCFs was mainly attributed to network collapse and buckling. This paper provided a fundamental insight into the mechanical properties and deformation mechanisms of the CBCFs under cyclic compression, which may contribute to the development for the new generation of reusable TPS.