Fatigue behaviour of composite tubes under multiaxial loading

40
max , MPa
| min |, MPa
Fifth International Conference on Fatigue of Composites
1000
800
600
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200
0
600
500
400
300
200
100
0
10 0
10 0
Woven CFRP laminate [(±45)/(0/90)] 3s
Experimental
RT 10 Hz
○ R = 0.1
▲ R = 0.5
10 1
10 2
10 3
2N f
(a) R = 0.1, 0.5
10 4
Predicted
10 5
Woven CFRP laminate [(±45)/(0/90)] 3s
Experimental
RT 10 Hz
□ R = 10
▼ R = -1
10 1
10 2
10 3
2N f
(b) R = -1, 10
10 4
10 5
10 6
Predicted
Fig. 12. Comparison between the predicted and experimental S-N relationships at room temperature.
The anisomorphic CFL diagram for fatigue loading at 100 o C was also compared with the
experimental results. From the comparisons, it was found that the asymmetric and nonlinear CFL
diagram for the woven CFRP laminate at 100 o C can adequately be predicted by the anisomorphic CFL
diagram approach.
The test results reveal that as far as the range of temperature from RT to a certain temperature
between 100 o C and 150 o C is concerned, the woven CFRP laminate tested in this study exhibits
monotonic reduction in static and fatigue strength with temperature and no significant collapse in
compressive fatigue strength. In that temperature range, the anisomorphic CFL diagram approach allows
adequately predicting the CFL diagram for any temperature and S-N relationships for any stress ratios.
5. Conclusions
The CFL diagrams for a woven fabric carbon/epoxy quasi-isotropic [(±45)/(0/90)]3S laminate at
10 6
10 7
10 7