Dynamic fatigue of two-dimensional carbon/carbon composites

The dynamic fatigue of a chemical vapor infiltration 2D-C/C composite was investigated in three-point flexure using different stress rates from 0.07 to 70 MPa s−1. Flexure strength of the specimens increased in proportion to the increase of stress rate. From the ln σ–ln σ̇ diagram, stress corrosion factor n was obtained. The n value of 58 in the present work indicated that slow crack growth controlled the fracture process. The fracture under different stress rates shows characteristics of the slow crack growth, which agree with the result of dynamic fatigue.