PSI - Issue 33

Fuzuli Ağrı Akçay et al. / Procedia Structural Integrity 33 (2021) 279 – 286 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Table 2. Experimental data of structural steels (Zhu & Engelhardt, 2018). ASTM A572 Gr. 50 steel AISI 1045 steel Test number �� ���� ε � � �� ���� ε � � 1 1.570 1.000 0.210 1.024 0.000 0.101 2 0.920 0.070 0.730 0.689 0.656 0.236 3 1.090 0.210 0.510 0.504 1.000 0.489 4 0.130 0.070 2.150 –0.255 0.608 1.183 5 1.570 1.000 0.200 0.819 0.100 0.157 6 1.080 0.070 0.710 0.813 1.000 0.231 7 1.280 0.070 0.530 0.780 0.000 0.177 8 1.140 1.000 0.390 0.671 0.000 0.218 9 1.150 0.640 0.430 0.620 0.848 0.277 10 1.120 0.610 0.370 0.375 0.518 0.355 11 1.150 0.440 0.480 0.205 0.244 0.403 12 1.090 0.330 0.420 –0.021 0.000 0.860 13 1.050 0.070 0.670 –0.169 0.383 0.966 14 0.540 0.640 0.930 N/A N/A N/A 15 0.480 0.430 1.300 N/A N/A N/A 16 0.450 0.400 1.140 N/A N/A N/A 17 0.340 0.170 1.680 N/A N/A N/A 18 0.140 0.070 1.860 N/A N/A N/A

2.2.3. Constitutive Equation von-Mises yield criterion (often called J2 plasticity) and the following power hardening law is utilized as a constitutive equation �� � � �� � (3) where �� and �� denote equivalent stress and equivalent strain, respectively. The strength coefficient, denoted as , and the hardening exponent, denoted as , of each material is given in the following section along with the results. 3. Results and Discussion Fracture loci of Al2024-T351 alloy ( � ��� MPa, � ���� ) determined by KAEB and MSS criteria are displayed in Figure 1. Pure shear test (Test #11) is utilized to calibrate both criteria. Figure 1 shows that MSS criterion leads to better accuracy if the friction coefficient in KAEB criterion is ignored. However, KAEB criterion becomes superior than the MSS criterion with an appropriate choice of the friction coefficient.