Issue 35

O. Demir et alii, Frattura ed Integrità Strutturale, 35 (2016) 330-339; DOI: 10.3221/IGF-ESIS.35.38 337 to the standard and crack deflection angles are measured from the fracture surfaces. Also, a 25 mm-thick CTS specimen is tested for 30° loading angle and its results are given in the table. Specimen No Specimen Type Loading Angle (°) Thickness (mm) Crack Length (mm) Pre-crack Load (kN) EXPERIMENTAL Critical Load (kN) Crack Deflection Angle (°) LT-01-150814-01 CTS 0 10.00 46.50 6.5 11.38 0.00 LT-01-251214-01 CTS 15 10.07 46.07 6.5 26.11 -9.41 LT-01-251214-02 CTS 15 10.06 45.96 6.5 26.68 -8.75 LT-01-150814-02 CTS 30 9.60 45.08 6.5 27.52 -26.85 LT-01-150814-03 CTS 30 10.10 44.94 6.5 28.59 -25.36 LT-01-150814-04 CTS 30 10.20 45.03 6.5 29.57 -26.42 LT-01-090215-01 CTS 30 25.00 46.51 6.5 60.23 -26.57 LT-01-150814-06 CTS 45 10.13 44.95 6.5 35.61 -35.71 LT-01-150814-07 CTS 45 10.17 44.75 6.5 33.00 -36.03 LT-01-220814-11 CTS 45 10.13 45.40 6.5 35.60 -36.54 LT-01-150814-09 CTS 60 10.16 44.93 6.5 46.25 -41.18 LT-01-150814-10 CTS 60 10.15 45.22 6.5 46.90 -41.11 LT-01-150814-12 CTS 60 10.18 45.20 6.5 45.71 - LT-01-251214-03 CTS 75 10.10 46.38 6.5 62.73 -50.66 LT-01-150814-04 CTS 75 10.14 45.24 6.5 68.07 -53.64 Table 2 : Experimental results of CTS specimen obtained from the mixed mode fracture tests. In Fig. 13, overall view of fracture surfaces from broken samples under 45° loads are given. As can be seen from Tab. 2 and Fig. 13, consistent fracture surfaces and deflection angles are observed from the tests for all loading angles. Figure 13 : Overall broken sample pictures and fracture sufaces of CTS specimen for 45° loading angle. Load-displacement curves and critical fracture load values for 45° loading angle are also given in Fig. 14. The critical fracture load is determined according to curve types listed in the ASTM E399 standard [19]. The procedure mentioned above is performed for all loading angle cases and obtained fracture loads are compared with some of the existing mode- I/II fracture criteria and are used to new mode-I/II fracture criterion. Figure 14 : Load-displacement curves of CTS specimen for 45° loading angle after fracture tests.