Dear Jason,

Recently I found a question about rainflow counting, In the FAST the half cycle are included in the rainflow counting ,But In the Bladed, there are no half cycles ,But the sum of counting is same. I really don’t know which way is most accurate .

Particularly,when the range is large ,if the counting have 0.5 gap,the DEL will make a big difference for example towerbase load.

What do you think?

rainflow counting.xlsx (13.6 KB)

Best Regard

Ruiliang

Dear Ruiliang,

I’m not sure how to comment on your results because I don’t know anything about Bladed’s rainflow counting algorithm.

In MLife (which is what I assume you mean when you refer to FAST), you have the option of choosing how to count unclosed cycles via input UCMult. UCMult=0.5 counts unclosed cycles as 0.5, but you could also set UCMult=0 to discard them, 1 to count them as full, or anything else between 0 and 1. You could always change UCMult to assess the sensitivity on the results. From my experience, the longer the time series, the less sensitive the value of UCMult will be. For example, instead of running 6 10-minute simulations, you could run 1 60-minute simulation or you could concatenate all 6 10-minute simulations into one 60-minute sample.

Best regards,