PSI - Issue 13

Emre Özaslan et al. / Procedia Structural Integrity 13 (2018) 535–541 M.A. Güler et al./ Structural Integrity Procedia 00 (2018) 000 – 000

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Fig. 6. (a) Grip section failure; (b) gauge section failure

5.3. Strength prediction of open hole specimens The PSC method needs unnotched laminate strength and characteristic distance to predict the notch laminate strength. Therefore, OHT2 specimens were used to find characteristic distance of this ply stacking sequence. After the tension testing, the strength of OHT2 specimens were found to be 306.1 MPa. Then finite element analysis was performed to find the characteristic distance by using OHT2 strength. The characteristic distance (d 0 ) was found to be 1.86 mm. Laminate stress distribution of OHT2 specimen in the loading direction is shown in Fig. 7.

Fig. 7. Loading direction stress distribution of OHT2 specimens

The strength of other specimens were also found by using PSC method. This method could predict the strength of specimens with maximum %8 error. In addition, it was seen that as the W/D ratio with constant specimen width (W) quadrupled, the failure strength rises %62.4. The accuracy of PSC method and the relation between W/D ratio and laminate strength is shown in Fig. 8.

Fig. 8. PSC predictions with test results