Abstract
Compressive behavior of 2D and 3D Carbon/Carbon (C/C) composite was investigated. 2DC/C showed relatively linear deformation up to the total fracture. However, 3DC/C showed large nonlinear deformation accompanying the load drop and recovery and no clear fracture was observed. In 2D specimen, the progressive microcracking was not observed during the testing, however, interlaminar delamination was observed. In 3D specimen, the microcracks didn't appear until the first stress peak of the δ-U curve, and after the peak, the delamination between X-Y bundle and shear failure of the Y bundle near the matrix pocket was observed. From the experimental observation, the initiation of the progressive fracture of 3DC/C was supposed as the interlamina delamination, which ruled the fracture of 2DC/C. However, the existence of Z directional fiber prevented the specimen from catastrophic failure. The fracture strength of both the C/Cs was discussed using micro-kinking model by Rosen and shear fracture model by Ewins & Ham.
