The 'data/sequences' directory contains simple loading sequences which can be used for testing easigrow. They have been previously used for exploring fatigue crack growth effects which are described in the two papers below.
In summary, the paper on rainflow counting showed that there was essentially no memory effect. So while reordering a sequence using rainflow counting works for crack growth, any process that reproduces the same crack extension will result in the same growth, based on crack extension occuring on the incresing loading part of the cycle e.g. if we have 10 repeated cycles going from 0.0 to 1.0. We will get the same growth if we have 10 cycles of 0--0.5 followed by 10 cycles of 0.5--1.0 . It seems that the stress ratio effect is more signficant for short periods of growth than is indicated from constant amplitude testing at higher stress ratios.
Secondly, the measurements on crack closure showed that the variations in crack grwoth rate at different stress ratios did not correlate with measurements of crack closure. Crack closure was very slow to build up, occuring over a distance of millimeters, whereas the change in growth rate due to different mean stress occured within a few cycles.
The papers are:
''' @Article{white14, author = {Paul White and David S. Mongru}, title = {Fractographic study on the use of rainflow counting for small and long cracks in {AA7050}}, journal = {Advanced Materials Research}, year = 2014, volume = {891--892}, pages = {687--692} }
@Article{white18, author = {P. D. White and S. A. Barter and N. Medhekar}, title = {Comparison of fractographic and strain gauge measurement of load ratio effects under variable amplitude loading}, journal = {International Journal of Fatigue}, volume = 112, pages = {240--252}, month = {July}, year = 2018 } '''