Md. Wang et C. Laird, DAMAGE AND FRACTURE OF A CROSS WOVEN C SIC COMPOSITE SUBJECT TO COMPRESSION LOADING/, Journal of Materials Science, 31(8), 1996, pp. 2065-2069
In order to understand the mechanical behaviours of ceramic matrix com
posites under various loading conditions, the compression stress-strai
n behaviour of a cross woven C/SiC ceramic matrix composite was charac
terized in terms of damage and fracture mechanisms, which were observe
d by scanning electron microscope (SEM) on a side-polished sample. The
compression stress-strain curve was found to consist of two stages. T
he first stage, which extends to about 300 MPa, covers linear elastic
deformation with a compression modulus of 140 GPa. The second stage st
arts with the occurrence of compression damage modes, which include pl
y delamination, bundle separation and transverse bundle cracking. Depe
nding on the local structure of the sample, the second stage of the st
ress-strain curve can be either mostly linear or non-linear. The fract
ure of the composite under compression is by kinking, shearing and ben
ding fracture of fibre bundles individually or in groups, forming a ma
croscopic shear band in the sample.