Influence of Near-Surface Residual Stresses on Strength of Ceramics

Abstract

The strength of ceramics is affected by residual stresses near the surface of a component. The stress profiles exhibit strong gradients and disappear within a few micrometers. Therefore, a fracture mechanical computation of the influence of residual stresses on strength requires the stress intensity factors under steep stress gradients to be known. The experimentally determined residual stress distributions available in literature can be sufficiently described by the superposition of exponential functions. The influence of residual stresses on strength is shown for the case of a maximum stress intensity factor criterion and for the case of preceding stable crack extension.