PSI - Issue 42

Tuncay Yalçinkaya et al. / Procedia Structural Integrity 42 (2022) 1651–1659

1657

Tuncay Yalc¸inkaya et al. / Structural Integrity Procedia 00 (2019) 000–000

7

(Avg: 75%) SDV126

0.0 0.1 0.2 0.3 0.3 0.4 0.5 0.6 0.7 0.7 0.8 0.9 1.0 −0.0 1.6

(Avg: 75%) S, Mises

1108 1267 1425 1583 1742 1900 3666

0 158 317 475 633 792 950

Fig. 2: Damage (Top) and Von Mises Stress (Bottom) distributions of VF15-Morph1-Oriset1 (Left), VF15-Morph1-Oriset2 (Middle), VF15 Morph1-Oriset4 (Right).

Fig. 3: True stress versus true strain curves of 37% volume fraction RVEs with three different orientation sets.

Next, the analyses are performed for three RVEs having the same morphology and martensite volume fraction of 37%. Similar to the 15% volume fraction example, the only difference between the simulated RVEs is the variation in the orientation set defined for the ferrite phase. Fig. 3 illustrates the resulting homogenized stress-strain curves. Anisotropy observed for the initial hardening stage can also be attributed to the low number of grains used in the RVEs. This time, differences in the flow curves are even more striking due to the less number of ferrite grains. Moreover, since there is an increase in the number of interfaces between the ferrite and martensite grains, softening observed in flow curves are more explicit, which indicates a decrease in the ductility for 37% volume fraction RVEs. Compared with the Fig. 1, as the number of martensite grains is increased, the strength of the material is also increased for each