LabVIEW Fatigue Analysis

[Serge67]

Definitely the rainflow counting algorithm VI has a bug in it. I've been getting unpredictable results with a dataset containing well defined high pulse. After a lot of frustrating and painfull debugging I found the root cause: in the State4 case when a full cycle is found and two points deleted from the array the index should not be reset to zero. It has to be decremented by 2. Zero will work for a simple small datasets but the real signals will buffer up more data in that array and setting index to zero is just wrong.

[nickbike]

Interesting. I'll have to look into this as I've been using this algorithm pretty heavily. Looking at the last activity of the original poster of this code, laiwei, it doesn't look like he/she is at NI anymore. I'm attempting to see if my company will purchase the ASTM E1049 spec so I can confirm the algorithm.

[nickbike]

scozza wrote:

                       

Hello Nick,

Thanks for the answer! Although it is old, It still necessary for me

Best wishes,

Scozza

Scozza,

    I've also been questioning how the Goodman correction works in this toolkit. If we do the calculations by hand in a spreadsheet, we get different results. I've turned to my own Goodman and Miner calculation VIs. Also, you might want to look into a paper called "Mean Stress Effects in Stess-Life and Strain-Life Fatigue" by Norman E. Dowling. It might make you turn your back on the Goodman correction all together. 

[hozaki]

Hi,

I would like to get a graph like attached file.

x axis is strain(amplitude) and y axis is counts.

Do you know which function should I use?

Or do you have any more details for those functions such as equation?

Thank you.

[Hazwani_12]

How can i find all the palette to build this labview fatigue analysis? 

[PWoodward]

I don't believe this toolset is working in modern versions of LabVIEW. We have run some tests against Matlab and Python scripts and it does not give the same results. This is even with each variation of peoples bug fixes in this forum chain.

[Scholerview]

Hello,

Thanks for your answer! 

I wonder how should I improve this VI.

[Scholerview]

Thanks for your share of these VIs.

I wonder if there is a detailed help document.