PSI - Issue 42

B.Aydin Baykal et al. / Procedia Structural Integrity 42 (2022) 1350–1360 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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integration point was above the selected critical stress. Critical volumes were calculated for critical stress values of 1500, 1750 and 2000 MPa. 2000 MPa was used as the basis for local approach to fracture calculations due to earlier literature showing that a critical stress of 1950-2050 MPa was the best fit for K Jc vs. T data (Bonadé et al., 2008).

Fig. 2: Mesh on 3D quarter 1T-CT specimen

3. Results

Fig. 3: Maximum principal stress map of 1T-CT specimen showing the critical volume (grey) for 2000 MPa critical stress Figure 3 highlights the results (maximum principal stress) from the 1T-CT simulation. The calculated critical volume is shown in grey. The critical stress, a fundamental variable in the local approach to fracture since the critical volume depends directly on it, is not very easy to determine. The impact of critical volume is demonstrated in Figure 4, which shows that the critical volume decreases non-linearly for the same displacement with increasing critical stress at a given temperature. Therefore, a priori knowledge of the critical stress pertaining to the material and conditions is important in order to be able to apply local approach to fracture with satisfactory accuracy.