LIFE2 fatigue analysis for wind turbine blades

Hello all,

I’m reading through literature to get caught up on the current techniques used for modeling the fatigue of wind turbine blades. I stumbled upon a Sandia program called LIFE2, which has a couple of articles and user guides listed online. Most of these seem to be pretty old; 1996 is the newest date I’ve seen.

I’d like to know if this code is still valid and if it is still used by anyone. If not, has something else replaced it? I see there is a fatigue code associated with crunch here on the NWTC list of codes.

I’m looking to incorporate fatigue into the FE analysis that I am doing on blades. Have these codes been used in conjunction with FEA? Does anyone know if there is a better way to model fatigue with FEA?

Regards,

Alex Quinlan
MS Candidate - Mechanical Engineering
Western Michigan University

Hello Alex,
I can tell you that LIFE2 is no longer supported at Sandia. In it’s day it was a very capable code. Nowadays we have tended to replace it with rainflow counting via Crunch and then we analyze the cycles in Matlab. With the ease and power you have in implementing relatively complex, custom fatigue failure models in Matlab, the need for LIFE2 slowly vanished. Still some of those old reports on the LIFE2 code are great resources for how to implement your analyses.

Hope this helps,
Brian Resor
Sandia

Alex,

Greg Hayman is preparing a full release of a new, MATLAB-based postprocessor called MLife. It is currently in alpha form, but we hope to have a beta release in the next few weeks. It is an extension of the lifetime calculations in MCrunch. Stay tuned for an announcement. If you subscribe to [url]http://forums.nrel.gov/t/software-releases/522/1], you will receive an email when we release MLife and other programs.

As a side note, the rainflow routine in Crunch (not MCrunch) is a modification of the one in Life2.

Marshall