This blog entry is a work-in-progress.
Fatigue analysis can be performed in the time domain using rainflow cycle counting. This is an elegant, brute-force approach. One advantage of the time domain approach is that it tends to highlight the occurrences of peaks above 3-sigma for the case of random vibration.
These higher peaks can also be accounted for in frequency domain methods, but the frequency domain approach requires a more thorough consideration of the Rayleigh distribution and other statistical theory.
Furthermore, the time domain method is better able to handle nonstationary and non-Gaussian time history inputs.
Here is a paper that gives a fatigue analysis example for a single-degree-of-freedom system subjected to a base input PSD using Rainflow cycle counting in the time domain: Miners_fatigue_rainflow.pdf
The method can readily be extended to the case of a multi-degree-of-freedom or a continuous system, as will be shown in future papers posted at this blog entry.
* * *
rainflow_bins.m is a Matlab script that performs rainflow cycle counting on a time history per ASTM E 1049-85 (2005).
A Matlab GUI version is included in: Vibrationdata Matlab Signal Analysis
Package
A Matlab MEX version is given at: Matlab MEX Rainflow
* * *
See also:
Synthesize a Time History to satisfy a PSD
* * *
– Tom Irvine
Contact Form:
[contact-form][contact-field label=’Name’ type=’name’ required=’1’/][contact-field label=’Email’ type=’email’ required=’1’/][contact-field label=’Website’ type=’url’/][contact-field label=’Comment’ type=’textarea’ required=’1’/][/contact-form]
1 thought on “Miner’s Cumulative Fatigue via Rainflow Cycle Counting”