- Tytuł:
- Thermomechanical modeling on the crack initiation of NiTi shape memory alloy
- Autorzy:
-
Jiang, Dongjie
Xiao, Yao - Powiązania:
- https://bibliotekanauki.pl/articles/29520078.pdf
- Data publikacji:
- 2022
- Wydawca:
- Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
- Tematy:
-
shape memory alloy
martensitic transformation
crack initiation
thermomechanical coupling - Opis:
- The fracture of shape memory alloys is distinct from that of conventional metals, owing to the coexistence and interaction of multiple special features such as martensitic transformation, dislocation-induced plasticity, thermomechanical coupling and others. In this paper, the impact of thermomechanical behavior upon the crack initiation of a NiTi shape memory alloy under Mode I loading is investigated numerically and verified experimentally. A constitutive model incorporating phase transformation, plasticity and thermomechanical coupling is established. Via backward Euler integration and finite-element implementation, the longitudinal strain, martensite volume fraction and temperature field in the vicinity of the crack tip are furnished. The effects of grain size and loading rate on J-integral are revealed. The grain size dependence of crack initiation is non-monotonic. For the samples with grain sizes of 1500 nm, 18 nm and 10 nm, the shielding effect takes place in front of the crack. Additionally, the anti-shielding effect is detected for samples with grain sizes of 80 nm and 42 nm. The parametric study shows that loading rate imposes limited influence on J-integral, which is attributed to a small scale transformation. The decrement of yield stress and the increment of transformation hardening modulus can alleviate the anti-shielding effect and arouse the shielding effect upon crack initiation. The presented results shed light on the design and fabrication of high toughness phase transformable materials.
- Źródło:
-
Computer Methods in Materials Science; 2022, 22, 1; 31-42
2720-4081
2720-3948 - Pojawia się w:
- Computer Methods in Materials Science
- Dostawca treści:
- Biblioteka Nauki
Artykuł