UNIAXIAL COMPRESSIVE BEHAVIOR OF AN ISOTROPIC GRAPHITE

Quasi static and dynamic uniaxial compression tests were performed on dumb-bell shaped specimen of a grade of graphite. The fracture of this kind of materiel is strain rate dependent. Indeed, we achieved two cl early different strengths. The graphite is less scattered compared to the ceramics. Its fracture seems brittle. However its mechanical behav iour is quasi linear elastic viscoplastic. At room temperature, this v iscoplasticity can be explained because of the exhibition of two combi ned physical phenomenon : glide motions of dislocations and mainly gro wth of microcracks slowed down by internal frictions.