Numerical analysis of NiTi actuators with stress risers: The role of bias load and actuation temperature

0563598 - FZÚ 2023 RIV GB eng J - Článek v odborném periodiku
Shayanfard, Pejman - Heller, Luděk - Šandera, P. - Šittner, Petr
Numerical analysis of NiTi actuators with stress risers: The role of bias load and actuation temperature.
Engineering Fracture Mechanics. Roč. 244, Mar (2021), č. článku 107551. ISSN 0013-7944. E-ISSN 1873-7315
Grant CEP: GA ČR GA18-03834S; GA ČR(CZ) GA20-14114S
Institucionální podpora: RVO:68378271
Klíčová slova: NiTi * shape memory alloy * thermal actuator * thermomechanical cycling * stress riser * notched ribbon * martensitic transformation * variable force * constant force * overheating
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 4.898, rok: 2021
Způsob publikování: Omezený přístup
https://doi.org/10.1016/j.engfracmech.2021.107551

NiTi wires and thin ribbons are used in shape memory actuators as active elements undergoing repeated thermal cycles. The NiTi actuators operate either under constant force (CF loading constraint) or they act against a variable force (VF loading constraint) from an elastic bias spring. Any stress riser represents a danger for potential actuator failure upon cycling. Although NiTi actuators always include stress risers either inherently in their design or as material flaws, their effect on actuation performance has, however, not been studied thoroughly yet. This issue is addressed in the present paper through numerical analysis of the effects of actuation load type (CF or VF loading constraint), maximum temperature, and stiffness of the bias springs (in VF loading constraint) on the local evolution of martensitic transformation (MT) and mechanical fields around the notch upon the cyclic thermomechanical loading of a thin NiTi shape memory notched ribbon.

Trvalý link: https://hdl.handle.net/11104/0335507