TY - JOUR
T1 - Tensile fatigue behavior of single carbon nanotube yarns
AU - Yang, Enlong
AU - Xu, Zhe
AU - Baniasadi, Mahmoud
AU - Moreno, Salvador
AU - Yi, Honglei
AU - Di, Jiangtao
AU - Baughman, Ray
AU - Minary-Jolandan, Majid
N1 - Funding Information:
Funding for this work was provided by the Visiting Scholar Fund of Jiaxing University and Natural Science Foundation of Zhejiang Province (LY18E030004). We thank Dr. Shaoli Fang for providing CNTY samples. We thank Dr. Gyu Kim for the help of fatigue test, Dr. Hongbin Lu for his laboratory and advice and Dr. Ali E. Aliev and Jiacheng Huang for the discussion. The authors declare that there is no conflict of interest.
Publisher Copyright:
© 2018, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2018/8/1
Y1 - 2018/8/1
N2 - In order to understand the tensile fatigue characteristics of single carbon nanotube yarn (CNTY), experiments of fatigue loading and residual strength after different fatigue cycles were conducted. Results show that the tensile fatigue limit of the CNTY is ~ 68% of ultimate tensile strength (UTS). SEM figures show a typical fatigue process including crack initiation, crack propagation, and sudden fracture. Helix angles on the surface of CNTY decreased when the yarn underwent a certain number of tension–tension fatigue loading cycles, and the yarn was increasingly strengthened. Specifically, the strength and modulus of CNTY were increased by 21% and 468%, respectively, when the yarn was subjected to a 105 fatigue cycles at 68% UTS. The increase in residual specific strength after cyclic loading was found out to be the reason for the inflection point of the S–N curve. However, there were gaps between the surface layer and inner layer in the yarn. Cracks initiated along the gaps by shear force and friction during cyclic loading. Then, the failure of the inner CNT layers was caused by stress concentration at one of the relatively large cracks. A sudden fracture of the CNTY occurred eventually.
AB - In order to understand the tensile fatigue characteristics of single carbon nanotube yarn (CNTY), experiments of fatigue loading and residual strength after different fatigue cycles were conducted. Results show that the tensile fatigue limit of the CNTY is ~ 68% of ultimate tensile strength (UTS). SEM figures show a typical fatigue process including crack initiation, crack propagation, and sudden fracture. Helix angles on the surface of CNTY decreased when the yarn underwent a certain number of tension–tension fatigue loading cycles, and the yarn was increasingly strengthened. Specifically, the strength and modulus of CNTY were increased by 21% and 468%, respectively, when the yarn was subjected to a 105 fatigue cycles at 68% UTS. The increase in residual specific strength after cyclic loading was found out to be the reason for the inflection point of the S–N curve. However, there were gaps between the surface layer and inner layer in the yarn. Cracks initiated along the gaps by shear force and friction during cyclic loading. Then, the failure of the inner CNT layers was caused by stress concentration at one of the relatively large cracks. A sudden fracture of the CNTY occurred eventually.
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U2 - 10.1007/s10853-018-2433-y
DO - 10.1007/s10853-018-2433-y
M3 - Article
AN - SCOPUS:85047161905
SN - 0022-2461
VL - 53
SP - 11426
EP - 11432
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 16
ER -