Weibull analysis and window lifetime prediction: a tutorial

Mechanical strength measurements of transparent ceramic window material coupons are customarily fit to a Weibull equation that describes the strength and its distribution. Predictions of window lifetime under stress are commonly based on slow crack growth parameters obtained by measuring the mechanical strength of coupons over a range of constant stress rates. This tutorial paper describes how to derive Weibull and slow crack growth parameters from strength measurements and how to use those parameters to predict window lifetime under stress. Proof testing is employed to ensure that a window begins its life with a known, minimum strength.