Template:Example:Eyring: Difference between revisions
Jump to navigation
Jump to search
Nikki Helms (talk | contribs) No edit summary |
|||
Line 8: | Line 8: | ||
<br> | <br> | ||
<br> | <br> | ||
[[Image:6stresstimefailed.png|center| | [[Image:6stresstimefailed.png|center|350px|''Pdf'' of the lognormal distribution with different log-std values.]] | ||
<br> | <br> | ||
<br> | <br> |
Revision as of 16:57, 3 April 2012
Eyring-Weibull Example
Consider the following times-to-failure data at three different stress levels.
The data set was analyzed jointly and with a complete MLE solution over the entire data set using ReliaSoft's ALTA yielding:
- [math]\displaystyle{ \widehat{\beta }=4.29186497 }[/math]
- [math]\displaystyle{ \widehat{A}=-11.08784624 }[/math]
- [math]\displaystyle{ \widehat{B}=1454.08635742 }[/math]
Once the parameters of the model are defined, other life measures can be directly obtained using the appropriate equations. For example, the MTTF can be obtained for the use stress level of 323K using:
- [math]\displaystyle{ \overline{T}=\frac{1}{V}{{e}^{-\left( A-\tfrac{B}{V} \right)}}\cdot \Gamma \left( \frac{1}{\beta }+1 \right) }[/math]
or:
- [math]\displaystyle{ \begin{align} & \overline{T}= & \frac{1}{323}{{e}^{-\left( -11.08784624-\tfrac{1454.08635742}{323} \right)}}\cdot \Gamma \left( \frac{1}{4.29186497}+1 \right) =16,610\text{ }hr \end{align} }[/math]