PSI - Issue 41

Fabio Distefano et al. / Procedia Structural Integrity 41 (2022) 470–485 Author name / Structural Integrity Procedia 00 (2019) 000–000

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was employed to predict the behaviour of Ti6Al4V ELI alloy, including the hardening effect due to the compression. The RADIOSS solver allows to apply a simplified Johnson-Cook material model by using the following equations: ܣ ൌ ߪ ௬ (5) ܤ ൌ ఙ ೠ ௡ఌ ೠ ሺ೙షభሻ (6) ݊ ൌ ఙ ೠ ఌ ೠ ఙ ೠ ିఙ ೤ (7) A, B and n are the parameters of the model. Table 3 reports the mechanical properties of the Ti6Al4V ELI alloy.

Table 5. Mechanical properties of Ti6Al4V ELI alloy E [GPa] ν

σ y [MPa]

σ m [MPa] 1006

ε m [%] 9.4

ε b [%] 17.3

ε 0 [s -1 ]

Ti6Al4V ELI 10 -3 Other Johnson-Cook parameters considered in the material model were obtained from data present in literature (Kotkunde et al., 2014), in which experimental tests were carried out with the same boundary conditions of the work (Epasto et al., 2019b). Thus, the Johnson-Cook constitutive model parameters of Ti6Al4V ELI alloy are presented in Table 6. 115 0.34 905

Table 6. Johnson-Cook constitutive model parameters of Ti6Al4V ELI A [MPa] B [MPa] C n

m

Ti6Al4V ELI 660 0.0093 0.505 0.7579 Moreover, the Johnson-Cook fracture model was simulated to show the relative effects of various parameters, such as: strain, strain rate, temperature and pressure. It also attempts to account for path dependency by accumulating damage as the deformation proceeds (Johnson and Cook, 1985). The fracture parameters of the Ti6Al4V ELI alloy (Zhang et al., 2015), are reported in Table 7. 905

Table 7. Johnson-Cook fracture model parameters of Ti6Al4V ELI D 1 D 2 D 3

D 4

D 5

Ti6Al4V ELI

-0.09 0.25

-0.5 0.014 3.87

Fig. 4 Boundary conditions of the FE model