Three-point bending fracture characteristics of three-dimensional-C/SiC with single-edge notch beam specimens

Loading-unloading properties of three-dimensional-C/SiC composites at ambient temperature were studied by three-point bending experiments with single-edge notch beam specimens. Crack growth was examined by scanning electron microscopy. The whole propagation process of a notch consists of a transient state and a steady state. The crack growth resistance is derived based on energy evaluation by a graphical method taking into account the non-linear fracture of the composites. The maximum value of the crack growth resistance, corresponding to the transition of the notch into cracks, reaches about 303.7 kJ m−2 when the ratio of equivalent crack length to sample thickness amounts to 0.13. The energy for the steady crack growth is about 20 kJ m−2.