PREDICTION OF SiAlON DIESEL VALVE FAILURE PROBABILITY USING AlliedSignal's CERAMIC AND ERICA LIFE PREDICTION CODES

摘要

The prediction of room temperature fast-fracturefailure probability of SiAlON valves, with 95% confidenceestimates of those predictions, were made through thecombination of censored flexure and tensile strengths of aSiAlON ceramic, their Weibull analyses, and finite elementanalysis of a prototype diesel exhaust valve, in AlliedSignal'sCERAMIC and ERICA life prediction codes. The life predictionalgorithm used, the finite element analysis, the dependence ofspecimen grinding parameters and specimen geometries (andtheir strengths), and "data pooling" on the resulting predictionsof failure probability are discussed. Within 95% confidence, thefailure probability predictions correlated quite well withexperimental fast-fracture strengths of SiAlON valves for allindependent parameters examined.