Low-Cycle Fatigue of TiNi Shape Memory Alloy and Formulation of Fatigue Life

1999 ◽  
Vol 122 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Hisaaki Tobushi ◽  
Takafumi Nakahara ◽  
Yoshirou Shimeno ◽  
Takahiro Hashimoto
Keyword(s):  
Fatigue Life ◽  
Elevated Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Silicone Oil ◽  
Low Cycle Fatigue ◽  
Fatigue Tests ◽  
Processing Temperature ◽  
Cycle Fatigue ◽  
Rotating Bending Fatigue

The low-cycle fatigue of a TiNi shape memory alloy was investigated by the rotating-bending fatigue tests in air, in water and in silicone oil. (1) The influence of corrosion fatigue in water does not appear in the region of low-cycle fatigue. (2) The temperature rise measured through an infrared thermograph during the fatigue test in air is four times as large as that measured through a thermocouple. (3) The fatigue life at an elevated temperature in air coincides with the fatigue life at the same elevated temperature in water. (4) The shape memory processing temperature does not affect the fatigue life. (5) The fatigue equation is proposed to describe the fatigue life depending on strain amplitude, temperature and frequency. The fatigue life is estimated well by the proposed equation. [S0094-4289(00)01102-6]

Low-Cycle Fatigue of TiNi Shape Memory Alloy and Formulation of Fatigue Life.

1998 ◽  
Vol 64 (626) ◽  
pp. 2548-2554
Author(s):  
Takahiro HASHIMOTO ◽  
Hisaaki TOBUSHI ◽  
Takafumi NAKAHARA ◽  
Yoshirou SHIMENO
Keyword(s):  
Fatigue Life ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

scholarly journals Impact of Temperature on Low-Cycle Fatigue Characteristics of the HR6W Alloy

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6741
Author(s):  
Grzegorz Junak ◽  
Anżelina Marek ◽  
Michał Paduchowicz
Keyword(s):  
Fatigue Life ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Tests ◽  
Total Strain ◽  
Cycle Fatigue ◽  
Fatigue Characteristics

This paper presents the results of tests conducted on the HR6W (23Cr-45Ni-6W-Nb-Ti-B) alloy under low-cycle fatigue at room temperature and at 650 °C. Fatigue tests were carried out at constant values of the total strain ranges. The alloy under low-cycle fatigue showed cyclic strengthening both at room temperature and at 650 °C. The degree of HR6W strengthening described by coefficient n’ was higher at higher temperatures. At the same time, its fatigue life Nf at room temperature was, depending on the range of total strain adopted in the tests, several times higher than observed at 650 °C.

Low Cycle Fatigue Properties of FGH720Li Superalloy

2021 ◽  
Vol 1035 ◽  
pp. 292-296
Author(s):  
Zi Chao Peng ◽  
Jun Ying Sheng ◽  
Xu Qing Wang ◽  
Yue Tang
Keyword(s):  
Fatigue Life ◽  
Powder Metallurgy ◽  
Applied Stress ◽  
Low Cycle Fatigue ◽  
Influencing Factor ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Nickel Base Superalloy ◽  
Loading Frequency ◽  
Cycle Fatigue

Low cycle fatigue (LCF) properties of a powder metallurgy(PM) nickel base superalloy FGH720Li were systematically studied in this work, including smooth LCF and notched LCF tested at various temperatures and different stress. The relationship between the fatigue life and applied stress was analyzed both for smooth fatigue and notch fatigue tests. The effects of loading frequency and stress ratio on LCF behavior were also studied. As an important influencing factor of the fatigue life in powder metallurgy superalloy, the effect of inclusions on LCF life was also investigated. The results showed that the fatigue properties of FGH720Li alloy was excellent, when tested at the temperature of 450°C and applied stress of 1230MPa, the fatigue life could exceed 5×104 cycles. When tested at 650°C and 1150MPa, the average fatigue life was still beyond 2×105 cycles.

Effect of Surface Finish and Loading Conditions on the Low Cycle Fatigue Life of Stainless Steel Welded Piping in PWR Environment

2013 ◽  
Author(s):  
Yuichi Fukuta ◽  
Yuichiro Nomura ◽  
Seiji Asada
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Austenitic Stainless Steel ◽  
Surface Finish ◽  
Loading Condition ◽  
Low Cycle Fatigue ◽  
Complex Loading ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Effect Of Surface

NUREG/CR-6909 of USA and JSME of Japan proposed new rules for evaluating environmental effects in fatigue analyses of reactors components. These rules were established from a lot of fatigue data with polished specimens under simple loading condition. The effects of surface finish or complex loading condition were reported in some papers, but these data were obtained with the simple shaped specimens. In order to evaluate the effects of surface finish and loading condition and to confirm the applicability of the proposed rules to actual components, Low Cycle Fatigue tests are performed in PWR environment with the specimens cut from 316 austenitic stainless steel welded piping. The pipes are machined to have three levels of surface finish condition and the load pattern simulating the thermal stress is applied to specimens. In this study, the effect of surface finish on fatigue life is included to be small for 316 austenitic stainless steel welded piping. Considering the insensitive region in the current evaluation rule, predicted accuracy is increased and possibility of improving the current rule is indicated.

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