A design exercise for a ceramic turbine disc subjected to centrifugal stresses

Abstract

A general procedure for the assessment of the failure probability of a stressed ceramic component is illustrated by a detailed study of a proposed turbine disc design. The procedure is based on a statistical approach using the Weibull probability distribution, and requires the evaluation of a stress integral over the volume or suface area of the component. The stress distributions in this case are obtained from a three-dimensional analysis of a photelastic model of the disc. The proposed design is critically appraised in the light of the derived stress integrals. The variation of failure probability with speed is illustrated and the effects of changes in the material properties of the prototype disc are quantitatively assessed.