Rainflow Cycle Counting

[rgordon]

Does anyone have a Mathcad Prime script for rainflow cycle counting for fatigue analysis that they would be willing to share or can anyone point me to an existing respource. I have several spectra I need to convert into stress histograms. The spectra each have more than 20,000 lines of data

[Werner_E]

Did you try to search this forum for "rainflow". There seem to be some hits - http://communities.ptc.com/message/92957#92957.

BTW, I just noticed you had a question two month ago. Ther were some replies but no reaction from your part!?

[VladimirN]

Hi,

Please find in attachment "Rainflow Counting" worksheet from the "DynamAssist (Structural Dynamics Toolbox)" e-book for Mathcad, which is available here: http://www.dynamassist.com/ . Another useful discussion: http://communities.ptc.com/thread/19166

[Werner_E]

VladimirN. wrote:

Hi,

Please find in attachment "Rainflow Counting" worksheet from the "DynamAssist (Structural Dynamics Toolbox)" e-book for Mathcad,

This file of Ian Ward is one of the two files from the thread I posted.

[VladimirN]

That is correct. Only the processed data are different.

[Raiko]

Hello Vladimir,

I keep getting error messages when using the MC14-MC15 Rainflow Counting function.

I'm using MC15 on a Win 7 machine and the error message reads "This array index is invalid for this array".

My vector has 9500 elements.

Any ideas?

Raiko

P.S.

The function is set to 100 bins. When and for what puropose should these bins be changed?

[VladimirN]

Hi Raiko,

Any chance to see your input data?

[Raiko]

Of course, here we go

Raiko

[Werner_E]

OK, thats it;-)

Set ORIGIN to 1 and it works.

When writing my last post I hadn't seen the sheet you sent.

[Werner_E]

when using the MC14-MC15 Rainflow Counting function.

I'm using MC15 on a Win 7 machine and the error message reads "This array index is invalid for this array".

My vector has 9500 elements.

Any ideas?

Hard without seeing anything. The original was created with ORIGIN=1 in mind (its set in the "range function" area. Did you consider this?

[Raiko]

Hi Werner,

thank you. It's working now!

Raiko