Dear Rachit,
I received your email. I am responding on the forum in the hope that whatever little insight I have into MCrunch may prove beneficial to other users of the forum. First of all, I am no expert on MCrunch or fatigue. I dabbled with it a little bit, because of the nice plotting features that Marshall Buhl has incorporated into it, which Crunch doesn’t have. And Marshall would be the best person to answer your questions since it is his code, although I believe that he has not actively worked on it for a while. Because of memory issues with large files, I also haven’t used MCrunch for a while. Referring to your questions below.
- You can use Crunch and Fatigue codes that NREL distributes to analyze fatigue. I am sure there are other codes out there but these codes read the data directly from FAST output files and will save you an extra post processing step.
- You may wish to refer to IEC 61400-1 standard. Annex G of the standard has a description for the methodology to extend the fatigue loads from simulations to the entire lifetime of the turbine.
- I am not sure how you would do this.
- I assume you mean FAST simulations. IEC has recommendations for these too. I believe it varies based on load cases for turbulent wind between 6 to 12 simulations at each wind speed. Someone with more experience will have to tell you if this is sufficient or more simulations are required.
You also had emailed me regarding the question I had posed in the topic [url]MCrunch issue with Rainflow Cycle Exceedance plot]. Marshall pointed me to the MCrunh theory draft manual which has some explanation on the fatigue life calculation. The link is available in the topic. I hope this helps.
Best Regards,
Subin.