Issue 39

S. K. Kudari et alii, Frattura ed Integrità Strutturale, 39 (2017) 216-225; DOI: 10.3221/IGF-ESIS.39.21 222 a T C C B 11 max 1 2 . .            (10) a T C C B 11-max 1 2 . .   (11) where, constant C 1 and C 2 are referred in this work as 3D geometric factors. The values of C 1 for various a/W and C 2 for various B/W for the CT specimen are tabulated in Tab.1 and Tab.2 respectively. a/W 0.45 0.50 0.55 0.60 0.65 0.70 C 1 1.5211 1.6115 1.7753 2.0094 2.3111 2.6775 Table 1 : Values of C 1 computed from Eq.(5). B/W 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 C 2 0.2331 0.3031 0.3600 0.4057 0.4425 0.4723 0.4974 0.5199 0.5417 0.5652 Table 2 : Values of C 2 computed from Eq.(8). The above Eq.(11) can be used to estimate T 11-max for the CT specimen for a given specimen dimensions and applied load,  . A typical plot of T 11-max computed from Eq.(11) is superimposed (Red curve) on 3D FEA results shown in Fig. 8. This plot shows a good agreement with the results estimated by Eq.(11) and 3D FEA. An error analysis is carried out between the estimated values from Eq.(11) and the present 3D FEA results. The maximum percentage of error in use of Eq.(11) for various B, a/W and  used in this study is found to be < 5.1%. The proposed analytical Eq.(11) is a simple method to compute T 11-max for the CT specimen geometry. Figure 9 : Variation of T 33 /  against B/W for various a/W. T 33 -stress The magnitudes of T 33 are estimated using Eq.(12) by substituting the extracted  33 (strain) from ABAQUS post processor and T 11 for varied  , B and a/W. T E T 33 33 11     (12)