Compression behaviors of carbon-bonded carbon fiber composites: Experimental and numerical investigations

Carbon-bonded carbon fiber composites (CBCFs) were widely used as thermal insulation materials due to their light weight and ultra-low thermal conductivity. The CBCFs with density of about 0.256 g/cm³ were tested in compression with the modulus and strength evaluated. The in-plane and out-of-plane tests revealed obvious anisotropic behavior of the material, which could be attributed to the fibers distribution. The unloading-reloading tests showed more evidence for the difference of the mechanical behaviors between in-plane and out-of-plane. In addition, we presented a finite element model to predict the mechanical properties of the CBCFs, and the deformation mechanisms as well. The numerical results showed the compressive modulus and strength increased with density following exponential functions. Moreover, the effects of fiber length and the fiber orientation on the mechanical properties were also discussed numerically. The results of this paper are helpful for the design and optimization of these materials for potential applications.