TY - JOUR
T1 - Multiscale TRIP-based investigation of low-cycle fatigue of polycrystalline NiTi shape memory alloys
AU - Zhang, Yahui
AU - Moumni, Ziad
AU - You, Yajun
AU - Zhang, Weihong
AU - Zhu, Jihong
AU - Anlas, Gunay
N1 - Publisher Copyright:
© 2018 Elsevier Ltd.
PY - 2019/4
Y1 - 2019/4
N2 - In this paper, a multiscale investigation of fatigue crack initiation in shape memory alloys (SMAs) based on Transformation Induced Plasticity (TRIP) is presented. A mechanism for fatigue crack initiation during cyclic stress-induced phase transformation along with theoretical model is proposed. To validate the TRIP-based model, quasi-static tests at different ambient temperatures, 40∞C, 52∞C and 65∞C, and strain and stress controlled low-cycle fatigue tests at different frequencies ranging from 0.16 Hz to 5 Hz on pseudoelastic NiTi wires are carried out. The results show that, (i) TRIP appearing on phase transformation interfaces is the key factor that drives the fatigue crack initiation during cyclic stress-induced phase transformation in SMAs; (ii) maximum temperature during phase transformation is a relevant indicator to predict low-cycle fatigue of SMAs and, (iii) within the range of pseudoelasticity and below the plastic yield, low-cycle fatigue of SMAs is not directly correlated with the mechanical loads applied at macro-scale, in the sense that, if the maximum temperature reached during loading cycles is kept constant, the fatigue lifetime remains unchanged whatever the amplitude of the mechanical loading is. Based on the findings, a new criterion for pseudoelastic low-cycle fatigue of SMAs as well as fatigue-isolines diagram are proposed and validated experimentally.
AB - In this paper, a multiscale investigation of fatigue crack initiation in shape memory alloys (SMAs) based on Transformation Induced Plasticity (TRIP) is presented. A mechanism for fatigue crack initiation during cyclic stress-induced phase transformation along with theoretical model is proposed. To validate the TRIP-based model, quasi-static tests at different ambient temperatures, 40∞C, 52∞C and 65∞C, and strain and stress controlled low-cycle fatigue tests at different frequencies ranging from 0.16 Hz to 5 Hz on pseudoelastic NiTi wires are carried out. The results show that, (i) TRIP appearing on phase transformation interfaces is the key factor that drives the fatigue crack initiation during cyclic stress-induced phase transformation in SMAs; (ii) maximum temperature during phase transformation is a relevant indicator to predict low-cycle fatigue of SMAs and, (iii) within the range of pseudoelasticity and below the plastic yield, low-cycle fatigue of SMAs is not directly correlated with the mechanical loads applied at macro-scale, in the sense that, if the maximum temperature reached during loading cycles is kept constant, the fatigue lifetime remains unchanged whatever the amplitude of the mechanical loading is. Based on the findings, a new criterion for pseudoelastic low-cycle fatigue of SMAs as well as fatigue-isolines diagram are proposed and validated experimentally.
KW - Fatigue crack initiation
KW - Low-cycle fatigue
KW - Shape memory alloys
KW - Thermomechanical coupling
KW - Transformation induced plasticity (TRIP)
UR - http://www.scopus.com/inward/record.url?scp=85058843736&partnerID=8YFLogxK
U2 - 10.1016/j.ijplas.2018.12.003
DO - 10.1016/j.ijplas.2018.12.003
M3 - 文章
AN - SCOPUS:85058843736
SN - 0749-6419
VL - 115
SP - 307
EP - 329
JO - International Journal of Plasticity
JF - International Journal of Plasticity
ER -