Status of the CERAMIC/ERICA Probabilistic Life Prediction Codes Development for Structural Ceramic Applications

Abstract

Statistical methods for design of ceramic components for fast fracture and time-dependent failure modes have been advanced to significantly enhance component reliability and reduce baseline data generation costs. The statistical methods are incorporated in AlliedSignal Engines CERAMIC and ERICA computer codes. Use of the codes facilitates generation of material strength and fatigue parameters by pooling data from specimens that are of varying sizes, stressed by dissimilar loading conditions, or tested at a variety of temperatures, and by including specimens that have been proof tested. The codes include approaches to calculate confidence bounds for Weibull and fatigue parameters of censored data as well as for predicted reliability of ceramic components. Rather than presenting highly detailed, previously published theoretical derivations (Cuccio, et al., 1994, Schenk, et al., 1998, Schenk, et al., 1999), this paper presents a summary of general methodology and a synopsis of code features and capabilities. The work was sponsored by the Department of Energy/Oak Ridge National Laboratory (DoE/ORNL) under Contract DE-AC05-84OR21400.