Analysis of accelerated life test data consists of an underlying life distribution that describes the product at different stress levels and a life-stress relationship (or model) that quantifies the manner in which the life distribution changes across different stress levels. These elements of analysis are shown graphically in Figure 5.
Fig. 5: A life distribution and a life-stress relationship.
The combination of both an underlying life distribution and a life-stress model can be best seen in Figure 6 where a pdf is plotted against both time and stress.
Fig. 6: pdf vs. time and stress
The assumed underlying life distribution can be any life distribution. The most commonly used life distributions include the Weibull, the exponential and the lognormal. Along with the life distribution, a life-stress relationship is also used. These life-stress relationships have been empirically derived and fitted to data. An overview of some of these life-stress relationships is presented in the Analysis Method subchapter.
The following chapters combine these relationships with life data models (i.e. life distributions) and present more detailed explanations of their use and applicability:
See Also:
Looking at a Single Constant Stress Accelerated Life Test
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