How to analyze two timevarying stresses

[Bryan Fox]

We are conducting a test on 4 samples of a new component, and I want to analyze the results. The test involves both temperature cycling and voltage cycling, at the same time. The problem is, the cumulative-damage model in ALTA only allows you to work with one stress column. How should I analyze my data? In the test, voltage is either applied or not applied as a way of aiding the chamber in transitioning to or maintaining a desired temperature. Hence, because energizing the component generates heat, the component is energized only when the chamber is trying to raise the temperature or when it reaches the upper temperature limit for the test. The component is de-energized when the chamber is trying to lower the temperature or when it reaches the lower temperature limit for the test.

Any help is appreciated.

[Pantelis]

Brian

It may be better to describe the cycling as a multiple constant stress problem instead of a time varying problem. I think it is similar to an Example we worked on in the QALT course (Look at your QALT notes (Example 6 - Slide 222)).

You may also want to see http://www.weibull.com/hotwire/issue19/hottopics19.htm

If you want to discuss further feel free to contact me directly.

Pantelis