An experimental study of carbon/carbon composites

To avoid well known difficulties in the testing of high-modulus and high-strength unidirectionally- and 3D-reinforced carbon/carbon composites arising because of the low shear and transverse strengths of the former and rough heterogeneity of the latter, special methods of evaluating the strength and stiffness characteristics and estimating their near-free-edge behavior are developed and analyzed. Unidirectional and cross-plied materials have been used in these experiments. Plane and cylindrical (tubular) specimens as well as cylinders of large size were tested. Special attention has been given to the behavior of composites under both non-stationary thermo-mechanical loading and one-side heating or lateral bending.