Issue 35

O. Demir et alii, Frattura ed Integrità Strutturale, 35 (2016) 340-349; DOI: 10.3221/IGF-ESIS.35.39 348 In Tab. 8, for the T-specimen experimental and predicted crack deflection angles obtained from the developed criterion using the CTS specimen data and predictions of other existing criteria in the literature for different loading cases are given. Specimen No Loading Angle (°) CRACK DEFLECTION ANGLES (°) Erdogan and Sih [1] Richard [10] Sih [2] Nuismer [3] Hussain [4] Koo and Choy [6] Developed Criterion Experimental Results T-LT-01-251214-01 0 0.00 0.00 0.00 0.00 0.00 0.00 - 0.00 T-LT-01-180115-12 15 -8.55 -10.52 -8.50 -8.55 -8.55 -4.09 -10.94 -11.73 T-LT-01-180115-13 15 -8.33 -10.27 -8.29 -8.33 -8.33 -3.98 -9.38 -9.34 T-LT-01-180115-14 30 -15.90 -18.39 -15.63 -15.90 -15.90 -8.28 -19.99 -21.95 T-LT-01-180115-15 30 -16.45 -18.95 -16.15 -16.45 -16.45 -8.64 -20.76 -18.07 T-LT-01-251214-02 45 -25.84 -28.25 -24.90 -25.84 -25.84 -16.77 -24.56 -26.26 T-LT-01-251214-03 45 -25.40 -27.83 -24.50 -25.40 -25.40 -16.29 -24.18 -24.15 T-LT-01-251214-04 60 -37.31 -39.59 -35.54 -37.31 -37.31 -34.12 -35.32 -33.69 T-LT-01-090215-18 60 -36.24 -38.51 -34.52 -36.24 -36.24 -32.26 -37.42 -36.41 T-LT-01-180115-17 75 -51.38 -54.85 -50.73 -51.38 -51.38 -54.33 -46.97 -50.19 T-LT-01-220215-22 75 -51.69 -55.20 -51.12 -51.69 -51.69 -54.65 -46.39 -52.06 Table 8 : Comparison of the predicted crack deflection angles using the developed criterion and comparison with other existing criteria in the literature, T-specimen. Comparison of experimental and predicted crack deflection angles for the T-specimen are presented in Fig. 4. As can be seen in the figure, all criteria show a similar tendency with each other and experimental results for all loading cases, except Koo and Choy criterion. Crack deflection angle values obtained from the developed criterion and experimental results are very close with an average error of 6.25% for all loading angles studied. Figure 4 : Comparisons of experimental and predicted crack deflection angles - T-specimen. C ONCLUSIONS n this study, fracture experiments of CTS specimen and a new type of specimen, called T-specimen, which has smaller dimensions and requires less material were conducted to check the validity of some of the existing criteria for mixed mode-I/II fracture conditions and to develop a further refined mode-I/II fracture criterion. A new improved empirical mixed mode-I/II criteria for onset of fracture and deflection angle were proposed and comparisons of the developed and existing mode-I/II fracture criteria in terms of fracture loads and crack deflection angles were presented. I