rfcnt 0.4.6

rfcnt a rainflow counting algorithm Python package

"Rainflow Counting" consists of four main steps:

1. Hysteresis Filtering

2. Peak-Valley Filtering

3. Discretization

4. Four Point Counting Method:

               * D  
              / \       Closed, if min(B,C) >= min(A,D) && max(B,C) <= max(A,D)  
       B *<--/          Slope B-C is counted and removed from residue  
        / \ /  
       /   * C  
    \ /  
     * A  
   

These steps are fully documented in standards such as
ASTM E1049 "Standard Practices for Cycle Counting in Fatigue Analysis" [1]
This implementation uses the 4-point algorithm mentioned in [3,4] and the 3-point HCM method proposed in [2] as well as the ASTM E 1049 (2011) standard in [1]. To take the residue into account, you may implement a custom method or use some predefined functions.

Install

pip install {packagename}.tar.gz --no-build-isolation --no-deps

where {packagename} is the current package release, for example:

pip install rfcnt-0.4.6.tar.gz --no-build-isolation --no-deps

Test

rfcnt packages include some unit tests, which can be run:

python -m rfcnt.run_tests

Examples

For a quick introduction you can run and inspect a small example:

python -m rfcnt.run_examples

References:

[1] "Standard Practices for Cycle Counting in Fatigue Analysis."
ASTM Standard E 1049, 1985 (2011). West Conshohocken, PA: ASTM International, 2011.
[2] "Rainflow - HCM / Ein Hysteresisschleifen-Zaehlalgorithmus auf werkstoffmechanischer Grundlage"
U.H. Clormann, T. Seeger
1985 TU Darmstadt, Fachgebiet Werkstoffmechanik
[3] "Zaehlverfahren zur Bildung von Kollektiven und Matrizen aus Zeitfunktionen"
FVA-Richtlinie, 2010.
[https://fva-net.de/fileadmin/content/Richtlinien/FVA-Richtlinie_Zaehlverfahren_2010.pdf]
[4] Siemens Product Lifecycle Management Software Inc., 2018.
[https://community.plm.automation.siemens.com/t5/Testing-Knowledge-Base/Rainflow-Counting/ta-p/383093]