Rainflow Counting Algorithm

Very fast rainflow cycle counting for MATLAB

Description

The rainflow algorithm code has been prepared according to the ASTM standard (Standard practices for cycle counting in fatigue analysis) and optimized considering the calculation time.

• MATLAB release: MATLAB 7.1.0 (R14SP3)
• Other requirements: The package includes MEX files for Win32 and Win64. For other OS the source code should be compiled.

[Yu Sang Hui]

This is the program that I want to find

[marc zbo]

helemaal top. Mijn dag is gelijk goed

[Zbo Amigo]

Lang naar gezocht, maar nu heb ik het dankzij ZBO!

[Jim Kay]

Program works well; does not produce histograms, you need to extract these yourself (watch out for half-cylcles).
Checked against "Simple rainflow counting algorithms" (1 pass methdo), Downing and Socie; got the same results.

[reshu shukla]

i want to know that the information about the counting method

[abdelkader miloudi]

 

[Steve Grobler]

Found teh demo quite informative. Would be helpful if the rainflow results could be arranged in a matrix of cycle counts, with the rows representing the mean, and the columns representing the ranges. Also be helpful if the "leftover" 1/2 cycles could be combined into full cycles and included in the matrix.

[muh alat]

 

[Ole Dossing]

This is a very fine application, not to mention the latest additions. We have used the the rainflow in a stay bridge for fatigue monitoring on critical structures.

[aid abdelkrim]

- the version matlab does not go
- I need the module mex.h
 
 

[Tomasz Bednarek]

 

[BB shine]

This program is perfect to me... thanks..

[hh hh]

 

[matt matt]

Once the entry vector is too large, it doesn't work. Who can help me?

[Joe Quinn]

Dr. Nieslony has developed a Rainflow counting application which we used to validate our impemtation of the ASME standard.
Once you know that his cycle size is peak and not peak to peak you can adjust (X2) and then it worked 100%.
Bins boundaries are based on the midpoint between succesive bin midpoints. This caused some juggling to match our method which specifies bin edge directly.
Otherwise, it was accuarate and easy to modify for graphing and printouts.

I am certain that had I been able to read it the Polish comments would have further added to my understanding of the code.

[Sarah Hughes]

Functionally this program is excellent, and produces results that are consistent with the ASTM standard. As with other users, it took me a while to realise that amplitude means amplitude and not range, but that's my fault for not reading it properly. I would appreciate some more explanation of the meaning of the half-cycles which I haven't encountered in other software, as I'm not sure how best to process these.

[Vikas Gupta]

This is very best in lot of applications.

[Andy Stevenson]

This is an excellent tool. I made a couple of short example problems to understand the output and once I did that I'm using the program at work. The rfdemo2 code is especially cool for showing others how rainflow counting works.

[gov raj]

good approach

[Matthew Hoehler]

A very useful tool! It is fast, robust and did just what I needed; no more, no less.

[rafiq zulkiffli]

need to show the soft code

[Adam Nieslony]

Hi Rafiq Zulkiffli,

Some years ago I wrote the rainflow function in MATLAB Script (m-file). Unfortunately the function worked very, very slow, because many iterations in the rainflow algorithm appears. So, I decide to create mex function where the time consuming iterations realized faster. Be sure, with ?the soft code? you cant count the cycles in sensible time. Look on the ?rainflow.c? file and try to understand the C code lines.

Best regards, Adam Nieslony

[muhd rafiq zulkiffli]

show the code for rain flow cycle counting

[Muhd rafiq]

thanks for the advice..but im still got problem coding in Matlab, because i cannot get the peak and valley reversal first..my data length is 32000 and sampling frequency is 200...can u give me some idea...
 

[rafiq zulkiffli]

hello,
i have 1 nonlinear equation with 2 unknowns, can u give the example solution using matlab??..this is my equation is
(0.003005*Nf^-0.072)+(0.8419*Nf^-0.56654)-((6.571*10^-7)*0.5)=0

[Kerim Genc]

Excellent code, very useful. I validated and understood it through trials with small data sets before moving onto huge force-time curves. Make sure that you understand that amplitude is in terms of a sinusoid, therefore the magnitude of the peaks are actually twice the amplitude indicated. Also, Half cycles can be a bit confusing at first, since this is not a "closed loop" rainflow counting method, you just have to combine the half cycles.

[Carmem Miranda]

I am taking Master course in Brazil. My research is on fatigue. I have difficulties to understand the input data for your program “Rainflow Couting Method”. I need a tutorial to the program and/or an input file example. Can you help me?
Thanks for attention

[arif fahruddin]

I'm master student, my thesis about fatigue in variable amplitude, random loaing. Have you a solution. Thank You

[Achalesh Pandey]

 

[David Outcalt]

Do you have a commented version of the C code? I find it difficult to follow.

[Jenyi Liao]

 

[nasri mohamed]

methode de rainflow par matlab

[Philips Adewuyi]

I have been looking for materials that treat the subject of rainflow counting methods for fatigue analysis of structures.

[aid Abdelkrim]

 

[syna gupt]

I used this toolbox but the result seems not correct....

[SENTHILKUMAR C.R]

 

[Félix DORE]

 

[Craig Chang]

great tool. Detail doc, easy to use. Excelent.

[santosh a]

 

[Filip R]

Hello
Does anyone know how to get output data from rfdemo1? Because i noticed that rainflow.m is not accurate with larger amount of data. Thank you

[Elena Menéndez]

Hello

I have noticed one important difference in the rainflow when compared with the rutine used by the software Bladed. The latter always assigns one full cycle to the range (max-min) of the timeseries. However, your rutine assigns 0.5 cycles to this range. Which one is more accurate?
Thank you

[ap1le q]

very good

[Andreas]

I can't get this working. I try the rfdemo1 using the syntax found in the rfdemo1.m, f.ex.
rfdemo1([2 3 2 4 2 5 1 6])

My error output is
>> rfdemo1([2 3 2 4 2 5 1 6])
??? Attempt to execute SCRIPT rainflow as a function:
C:\Users\Andreas\Documents\MATLAB\Rainflow cycle counting\rainflow.m

Error in ==> rfdemo1 at 35
a=rainflow(ext,1);
 
>>

Anyone know why?

[Andreas]

I found out that my first error came from a conflict caused by a similar filename and function name (Rainflow.m/rainflow) But now my error is:
??? Undefined function or method 'rainflow' for input arguments of type
'double'.

Error in ==> testinterpolasjon at 19
rf = rainflow(ext,exttime);

I'm running Matlab release 2009a

[S_Sampathkumar Sampathkumar]

On Elena Menéndez's question above, is there an answer. I am finding that amplitude is half the range as well in this method.? Anyone knows why?

"I have noticed one important difference in the rainflow when compared with the rutine used by the software Bladed. The latter always assigns one full cycle to the range (max-min) of the timeseries. However, your rutine assigns 0.5 cycles to this range. Which one is more accurate? "
 

[Jinsuk Lee]

I have temperature data over time and derive a fatigue model. Using this rainflow counting, I want to get data with three parameters, which are Max_termperature, each cycle time, amplitude (max-min). Is anyone knowing if this package can provide this kind of data? I appreciate.

[Ray Beale]

Sampathkumar- Amplitude is always half the range, by definition.

I am finding many half-cycles in my rfc output of a long time history. Another method I've used produces full cycles. When comparing the two methods for the same time history, the histograms have the exact same shape but your method is shifted to the right due to the unpaired half cycles. Both claim to be ASTM standard. Any idea why?

[Claudio Pedrazzi]

First of all, let me compliment for this excellent piece of software!!

The ASTM standard E 1049 -85 (2005) defines two distinct rainflow algorithms:
A) 5.4.4 "Rainflow counting" (that produces half-cycles)
B) 5.4.5 "Simplified rainflow counting for repeating histories" (that never produces half-cycles)

this is probably the answer to questions like the one of Ray Beale. Now I am interested in the "B" method, and I am asking the author: which algorithm is implemented here? my guess is the "A" method, with half cycles.
Second question: is there some hope to extend this function to be able to compute, optionalyy, also the B way?
If necessary I would be glad to provide more info (namely the text of the ASTM standard).
Best regards and thaks a lot for sharing!
Claudio

[Badrinath Veluri]

It is very good work

[Ahmed Farag]

I have a problem running the rfdemo1 file , i got this error message
?? Attempt to execute SCRIPT rainflow as a function.

Error in ==> rfdemo1 at 35
a=rainflow(ext,1);

Any solution for that

[Ahmed Farag]

Thanks Adam for your effort and you response to my enquiry, i really appreciate such an awesome routine

[Ahmed Farag]

 

[massimo]

how to import data in rfdemo2?
Lesson 2 from the html guide works, but what is the syntaz for
s=my_signal
Great work

[upna fruit]

Hi everone,
I'm working on fatigue testing and I'm using the rainflow algorithm with long and quite complex signals.
reading thought rfdemo2 I've noticed that the function
sig2ext is called twice. Is that necesary?
I will be gratefull of any help

[upna fruit]

Hi everyone,
First of all, thanks for your quick response in the previous comment I made. I'va keep on working on fatigue testing and I've found another problem.
I am analysing some test data with this algorithm but another research center is analysing the same data and they are reaching diferent results. They are using the algorithm of Downing and Socie "Simplified Rainflow Counting method".
Is it normal that we obtain different results because of that?

Thanks in advance

[Scott Richardson]

Hello, my question is regarding the example provided. It's an example, I realize, but I need to know if we're talking about the same thing because it's SO different from what I am used to seeing.

Namely, the slope used is 'm=8', and I am used to seeing slopes for steel of like -0.07. so that makes no sense.

Can someone please provide some clarification of what is meant there.

Thank you.

[Adam Nieslony]

According message from Scott Richardson, 09 Oct 2010.

There are more than one equation for stress-life characteristics. Probably you are working with the Basquin model:

    Sa=Sf*(2*Nf)^b

where b is understood as the curve slope. In my example the Wohler model is used. It is possible, with some restriction, compute the 'm' slope on the basis of Basquin model:

    m=-1/b

But remember that the first step is clarifying which kind of curve you are using. The Miner rule n/N=1 is used anyway.

Best regards, Adam Niesłony

[Scott Richardson]

Thank you very much Mr. Nieslony.

[Scott Richardson]

Might someone have a data set, with a known answer, to be able to run and understand clearly what the concerns cited above are. Or at least to help understand the nature of what has some concerned about. I want to be sure to not misunderstand something and I don't have data that can help me get to that point. Thanks very much in advance.

[Andrew Greaser]

Hello, My question is, how is it determined in the rainflow algorithm what stress ranges and cycle counts are put into each bin to create a rainflow histogram?

[Adam Nieslony]

Hi Andrew Greaser,
The RFHIST counts cycle amplitudes and not ranges. You can also make an histogram for cycles mean, frequency and period. See help lines included in RFHIST function.

[Andrew Greaser]

Thanks Adam,
I didn't phrase my question correctly, I understand the RFHIST counts cycle amplitudes and not stress ranges now, but what I am trying to figure out is if my rainflow function outputs - rf(3,:) Number of cycles (0.5 or 1.0) and my RFHIST syntax is [no,xo]=rfhist(rf,30) how does the program determine the bin locations or is rf evenly distributed over 30 bins or are the bin locations associated with the number of extracted cycles? Can you please elaborate on this.

Thanks

[Chris McCorquodale]

Hi,
I am quite new to matlab but can anyone tell me if this algorithm can give an output of number of cycles to failure? I am interested to know when a component (modelled in FEA) is going to fail.

Regards,
Chris

[Dilip Rao]

 

[Dilip Rao]

I would like to know if I have a lot of rainflow matrices,how do I add them.
ex. I have data from 3 axes of a sensor and from 3 sensors and I just need one rainflow matrix for all this data.The data for each axis and each sensor is huge.so I would like to know how do I get just one rainflow matrix for all the data?

[Adam Nieslony]

Hi Dilip Rao,
You can add the matrices without problems if they have the same size: m=m1+m2+m3. I don't know what you need exactly to do, but be careful while adding matrices from different sensors - maybe you have multiaxial fatigue problem? I this case use some theoretical criteria for obtaining equivalent uniaxial fatigue loading/matrix.

[Dilip Rao]

HI Adam,
The problem is the matrices are of different sizes and are really huge.Like I have 5 test cycles and x axis data from each cycle of different durations.I cannot add all the cycles as it is huge amount of data,so now can you suggest me how do I take a rainflow of all the cycles combined in one result?

[Dilip Rao]

Thank you Adam.I did add the rainflow matrices from every axis separately.

[Ahmed]

Hi,
 I downloaded the files and tried to run some numbers.
My input was [4 12 7 14 -5 4 -9 7 -1 16].
According to the rainflow method I am familiar with, I expected to get somthing similar to
[4 14 7 12 -5 4 -7 16 -1 7].
Instead, I got the matrix rf with Mean, Amp. , Half/full cycle, begining time and cycle period.

My question is, is it possible to get the result I expected,
i.e. [4 14 7 12 -5 4 -7 16 -1 7].

Thanks in advance,
Ahmed

[Shashank Chauhan]

Dear Adam

I am getting the problem as some have previously posted.

?? Attempt to execute SCRIPT rainflow as a function.

Error in ==> rfdemo1 at 35
a=rainflow(ext,1);

Can you suggest how should I overcome this.

Thanks

Shashank

[Benjamin]

First of all, thanks for sharing this awesome tool!

I have a similar problem on my linux pc running Matlab R201b:
??? Attempt to execute SCRIPT rainflow as a function:

Any help on that? :)

Ben

[Ramon]

Dear Adam

I have the same issue of Shashank (23Feb2011). And seems that rfdemo1 calls to rainflow.m that is the description.

Furthermore folloing the instructions I cannot check a simple input like b in the example below. I cannot run the rainflow. I'm not skilled yet on matlab maybe I miss something. Please could orientate us a little bit? thanks
>> rfdemo1
??? Attempt to execute SCRIPT rainflow as a function.

Error in ==> rfdemo1 at 35
a=rainflow(ext,1);

>> b

b =

    -2 1 -3 5 -1 3 -4 4 -2

>> rf=rainflow(b)
??? Attempt to execute SCRIPT rainflow as a function.

>>

I'm using matlab V7.0.1.24704 R14

[Shashank Chauhan]

I got it working.

The idea lies in renaming the rainflow.m to rainflow_1.m or any other name. The demo script rfdemo1 then executes the rainflow.mex which is what is intended.

[Ramon]

Dear Adam,

at the end works fine. I didn't read properly the help file to compile the Mex funtion to get the rainflow.dll. So for everyone that may have the same problem please read the help carefully.

I made some checks with my working current signals and works fine. It helps a lot to my work thank you very much for sharing it.

Best regards
Ramón

[pietro]

This function is great, the only bad point is the lack of a message, when overflow or underflow occour

Best regards

Pietro

[Abhishek Modi]

dear Adam,
I have a small question. I am currently working on a suspension model made in solidworks and i have translated it to simmechanics.i need to calculate the amount of fatigue present .i have been given a load cycle vs time and want to implement it .How can i do it here?

[kai]

dear Adam
thank you for your sharing, and there is a question that how can I get the "cycle_begin_time, cycle_period_time" in the "rainflow.c". And how can I make a 'rfhist' input, the format of 'rfhist'.

[JAEWOO PARK]

dear Adam,

hi~ I started to study MATLAB just before. I got a problem that I can't input a data to your algorithm. Can you give me an example with inputing some numbers?

Thank you

Jay Park

[JAEWOO PARK]

Fanally, I found it.

[JAEWOO PARK]

it was wrong......

[JAEWOO PARK]

Dear Adam,

Thank you for your advice, I got the results I wanted from rfdemo1. But I don't know how to get similar results like 'amplitude, mean, number of cycles (cycle or half cycle), begin time of extracted cycle or half cycle, period of a cycle' using rfdemo2. I need to input a lot of data and get the results like list in rfdemo1 using input data like vibrations. Thank you a lot.

Best regards

Jay Park