Strength predictions for notched alumina specimens

Ceramics fail in most cases by unstable extension of natural defects. Whilst strength measurements are mostly available for simple rest specimens, it is of practical interest to develop procedures which allow to predict the strengths of more complicated components. Several possibilities are considered which are based on a principal stress criterion, a fracture mechanics procedure using single cracks (including stress gradients and R-curve behaviour), and on a procedure which applies multiaxial Weibull statistics to the surface and volume defect population. (C) 1998 Published by Elsevier Science Limited.