Graphite single crystal elastic constants

Table 1 Elastic constants of graphite single crystal (23)...

From these considerations on elastic constants of the graphite single crystal we can derive the structural precondition for this technically interesting anisotropic polymer carbon. 

Carbon fibers type HM (high modulus) are carbon fibers with a value of Young s modulus (tensile modulus) larger than 300 GPa (nearly 30 of the Cn elastic constant of a graphite single crystal). 

The level of the tensile modulus o/carbon fibers is controlled by the degree of preferred orientation of the layer planes in the direction parallel to the fiber axis. Cjj, the elastic constant of graphite single crystals in the direction of the layer planes is 1060 20 GPa. In general, the ratio of tensile strength to tensile modulus is smaller than 1-lCf for carbon fibers type HM (but the tensile strength is influenced by flaws in the fibers and may be improved in the future). 

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