PSI - Issue 42

169 7

Lucas Carneiro Araujo et al. / Procedia Structural Integrity 42 (2022) 163–171 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

Fig. 3. Comparison of fatigue data of specimens with micro hole of 550 μm and Findley ’s model predictions.

The MWCM prediction maintains the conservative trend but with better prediction for uniaxial and in-phase data, with points below 20% error. For out-of-phase data as Findley’s it also remained at 30%. As can be seen in Fig. 4.

Fig. 4. Comparison of fatigue data of specimens with micro hole of 550 μm and Findley ’s model predictions. The performance of the models was evaluated by an error index, , where positive values mean that the predictions were conservative. The error index compares the relative difference between the experimental result ( ) and the predicted one ( ). The mean and maximum values of the errors are reported in Table 2. Where can be observed that MWCM provide better results for almost all loading and specimen condition, except for out-of-phase loadings with smooth specimen. = − × 100% (17) Table 2. Mean and maximum values of the error index, (%) . Condition Loads Findley MWCM Average Maximun Average Maximun

Uniaxial and In-phase

30.49 26.90 13.73 29.88

43.46 37.07 19.12 39.51

21.65 31.38 10.51 29.34

27.66 35.96 16.13 38.46

Smooth Specimen

Out-of-phase

Uniaxial and In-phase

Specimen with micro hole 550 μ m

Out-of-phase