Fatigue crack growth behavior of a randomly oriented short carbon fibe
r reinforced polyether ether ketone (PEEK) composite is studied at fou
r different load ratios. Based on the experimental data, a new fatigue
crack growth model is proposed which accounts for crack growth throug
hout the entire fatigue cycle and not just at the maximum load. The pr
oposed model involves a weighted averaging procedure and is found to f
it the fatigue crack growth rates at all load ratios in a single power
law equation. Finally, it is observed that the fatigue threshold inte
nsity of this material decreases with increasing load ratio.