FEM-LIFTAP, A Finite Element Lifetime Analysis Postprocessor for Ceramic Components
In recent years, several failure probability postprocessing programs for FE-codes applied to ceramic components have been developed. All postprocessors combine the statistical strength description according to Weibull with different strength theories as for example the ‘Principal Stress Theory’ linked to the ‘Principle of Independent Action’ or the ‘Linear Elastic Fracture Mechanics’ approach, both accounting for multiaxialloading. Moreover, the program includes a ‘Lifetime Processor’ which allows the calculation of the time-dependent failure probability of the ceramic component if strength degradation occurs due to subcritical crack growth. In a typical example, the time-dependent failure probability of an automotive ceramic exhaust valve was calculated using the mean value of the positive principal stresses as strength criterion.
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- 3.Ritchie, R.O and Dauskardt, R.M, Cyclic fatigue of ceramics: A fracture mechanics approach to sub critical crack growth and life prediction, to be published in J. Ceram. Soc. Jap., 1991, 99.Google Scholar
- 6.Lauf, S, Pabst, R.F, Strength-probability-time diagrams and the strength function — A critical examination. In Ceramic Materials and Components for Engines, eds. W. Bunk, H. Hausner, DKG, Bad Honnef, 1986, 961–977.Google Scholar
- 7.Stanley, P, Fessler, H and Sivill, A.D, An engineer’s Approach to the prediction of failure probability of brittle components. In Proc. Brit. Ceram. Soc., ed. D.J. Godfrey, BCS, Stoke-on-Trent, 1973, 22, 453–487.Google Scholar
- 10.Ikeda, K, Igaki, H and Kuroda T, Fracture strength of alumina under uniaxial and triaxial stress states, Am. Ceram. Soc. Bull., 1986, 65, 683–88.Google Scholar
- 11.Jayatilaka, A. de S., Fracture of Engineering Brittle Materials, Appl. Sc. Publ., London, 1979.Google Scholar
- 12.Creyke, W.E.C, Sainsbury, I.E.J and Morell, R, Design with Non-ductile Materials, Appl. Sc. Publ., London-New York, 1982.Google Scholar
- 14.Nemeth, N.N, Manderscheid, J.M and Gyekenyesi, J.P, Ceramic analysis and reliability evaluation of structures (CARES), NASA Technical Paper 2916, 1990.Google Scholar
- 15.Magerl, F, unpublished, University of Stuttgart, 1989.Google Scholar
- 16.Nemeth, N.N, Manderscheid, J.M and Gyekenyesi, J.P, Design of ceramic components with the NASA/CARES computer programm, NASA Techn. Mem. 102369,1990.Google Scholar