MODELING OF CREEP OF ALIGNED SHORT-FIBER REINFORCED CERAMIC COMPOSITES

A model is developed to predict the steady-state creep behavior of aligned short-fiber reinforced ceramic matrix composites. The approach is based on an advanced shear-lag model. The analysis incorporates some unique characteristics of ceramic matrix composites, such as the fiber/matrix interface sliding effect, shear and axial loads carried by the matrix, and the fact that both the fibers and matrix creep at elevated temperatures. Several parameters, such as fiber volume fraction, fiber aspect ratio and the sliding factor at the interface, are varied to determine their effect on creep behavior. Finally, the results from the model are shown with experimental data of an SiC/Al2O3 composite, although this is not meant as a direct comparison because of the uncertainty of the material properties and geometric parameters, and the fact that the experimental results are based on random fiber orientation, whereas the analysis assumes aligned fibers. © 1989.