CREEP-RUPTURE IN CERAMIC-MATRIX COMPOSITES WITH CREEPING FIBERS

A model has been developed for crack growth in an elastic matrix with creeping fibers. Specific solutions have been presented for the steady-state crack growth rate. These solutions provide straightforward connections to the constituent properties through well-known parameters that characterize matrix cracking with elastic fibers. An expression has also been given for the time taken to extend matrix cracks across the plies, as a preliminary estimate of the creep rupture life. A significant finding is the strong stress dependence of the life, even when the fibers creep linearly with stress.