Micromechanical modeling of damage and failure mechanisms in C/C-SiC

This paper deals with modeling of damage and failure mechanisms observed in 2D C/C-SiC composite samples loaded by tension, shear and compression. In a specimen subjected to tension, the early stage of damage is characterized by transverse cracking. Further load increase induces fiber failure in the longitudinal plies, which leads to fracture. Sheer loading gives origin to cracks oriented at 0 degrees/90 degrees and 45 degrees to the fiber axes, the latter causing fracture. Specimens loaded in compression exhibit catast rophic failure due to microbuckling of fiber bundles. Micromechanical model s are formulated for the discussed mechanisms. Results of numerical simulat ions show good agreement with experiments and the ability of the model to d escribe more complex loadings. (C) 1999 Elsevier Science B.V. All rights re served.