Abstract
Reliability estimation is usually performed on a part under a constant stress level. However, a part could experience several different stress levels, or profiled stress, during its lifetime. One such example is when the part is subject to step-stress accelerated life testing. Studying the reliability estimation & its confidence bounds for a part under varying stresses will generalize the existing estimation methods for accelerated life testing. In this paper, we derive the reliability function of a part under varying stresses based on a Weibull failure time distribution, and cumulative damage model. The reliability confidence bounds, based on a s-normal approximation, are given explicitly, and their limiting properties are discussed. A step-stress accelerated life testing example is used to illustrate these interesting properties, which provides the insights of the limitation of the current test plan, and how to design a better one.
Original language | English (US) |
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Pages (from-to) | 7-17 |
Number of pages | 11 |
Journal | IEEE Transactions on Reliability |
Volume | 55 |
Issue number | 1 |
DOIs | |
State | Published - Mar 2006 |
Externally published | Yes |
Keywords
- Accelerated life test
- Confidence interval
- Cumulative damage model
- Maximum likelihood estimation
ASJC Scopus subject areas
- Safety, Risk, Reliability and Quality
- Electrical and Electronic Engineering