Strain Rate Sensitivity of C/C Composites under Compression

To understand the strain rate sensitivity of compressive strength of carbon clothe/carbon (C/C) composites, quasi-static and dynamic compressive experiments were conducted in its x-y plane by means of electric universal test machine and Split Hopkinson Pressure Bar with pulse shapers. The experimental results show that the dynamic compressive fail strength of C/C composites has strong stain rate sensitivity and it increases with strain rate. Compared with the quasi-static compression, the dynamic compressive strength is higher by 70% or so. Meanwhile, the samples are failed by shearing under quasi-static loading, and by crushing under dynamic loading. The different mechanical behaviors from the experimental results indicate that it may be related to the strain rate sensitivity of interfaces characteristic of C/C composites and the change of the failure modes.