Fatigue Crack Paths 2003

14.5

12

9.5

7

4.5

2

-0.5

0

5 10 15 20 25 30

-3

-5.5

-8

-10.5

-13

Crackpath inferred fromalgorithm

-15.5

Figure 5. Fatigue crack path inferred by processing thermoelastic images captured

during a fatigue test performed at R = 0.1

5 . 4 1 4 1 0 2 . 9 e f f K d a Δ × = −

0.000001

Fitted growth law

dN

R=0.13

R=0.6

0.0000001

0.00000001

0.000000001 1

10

100

Effective stress intensity factor range, M P a √ m

Figure 6. Fatigue crack growth rate against the effective Δ Krange for fatigue tests

conducted at different R-ratios using TSA.