International Society of Science and Applied Technologies |
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Weibull Lifetime Model Considering Stress-Dependent Parameters | ||||
Author | J. Juskowiak
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Co-Author(s) | M. Bartholdt; B. Bertsche
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Abstract | Different Weibull lifetime models are presented whose scale, shape and minimum lifetime parameters are stress-dependent. This allows to describe and predict the lifetime of products with a Weibull distribution more accurately wherever stressdependence applies to the failure mechanism as is the case in e.g. failures due to fatigue on which this paper focusses. The proposed procedure encompasses a two-step maximum likelihood estimation and a Fisher matrix confidence bounds calculation followed by a model evaluation. This model evaluation is conducted by means of a general plausibility check, likelihood ratio test and Bayesian information criterion. Their applicability to accelerated life test data is discussed and validated using test data.
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Keywords | Stress-dependent Weibull Parameters, Non-constant Shape Parameter, Accelerated Life Test, Maximum Likelihood Estimation | |||
Article #: 21261 |
August 6-8, 2015 - Philadelphia, Pennsylvia, U.S.A. |