The Effect of Strain Rate on Low Cycle Fatigue Life with Hold Time for USC Candidate Rotor Material

2010 ◽  
pp. 217-229
Author(s):  
Kuk-cheol Kim ◽  
Byeong-ook Kong ◽  
Min-soo Kim ◽  
Sung-tae Kang
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Low Cycle Fatigue ◽  
Hold Time ◽  
Cycle Fatigue

scholarly journals Fatigue life time modelling of Cu and Au fine wires

2018 ◽  
Vol 165 ◽  
pp. 06002
Author(s):  
Golta Khatibi ◽  
Ali Mazloum-Nejadari ◽  
Martin Lederer ◽  
Mitra Delshadmanesh ◽  
Bernhard Czerny
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Load Ratio ◽  
Life Time ◽  
Material Model ◽  
Cycle Fatigue ◽  
Rate Dependency

In this study, the influence of microstructure on the cyclic behaviour and lifetime of Cu and Au wires with diameters of 25μm in the low and high cycle fatigue regimes was investigated. Low cycle fatigue (LCF) tests were conducted with a load ratio of 0.1 and a strain rate of ~2e-4. An ultrasonic resonance fatigue testing system working at 20 kHz was used to obtain lifetime curves under symmetrical loading conditions up to very high cycle regime (VHCF). In order to obtain a total fatigue life model covering the low to high cycle regime of the thin wires by considering the effects of mean stress, a four parameter lifetime model is proposed. The effect of testing frequency on high cycle fatigue data of Cu is discussed based on analysis of strain rate dependency of the tensile properties with the help of the material model proposed by Johnson and Cook.

Parameter Analysis for Time-Dependent Low-Cycle Fatigue Life

1994 ◽  
Vol 116 (4) ◽  
pp. 479-482 ◽  
Author(s):  
Koji Yamaguchi ◽  
Kazuo Kobayashi ◽  
Kiyoshi Ijima ◽  
Satoshi Nishijima
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Low Cycle Fatigue ◽  
Austenitic Stainless Steels ◽  
Original Data ◽  
Parameter Analysis ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Well Test ◽  
Design Code

Temperature and strain rate dependences of low-cycle fatigue life can be represented by a modified Larson-Miller parameter. The parameter P is written by P=T(logN25−Alog ε˙ + B), where T is temperature, N25 is fatigue life, ε˙ is strain rate, and A and B are constants. In the analysis, each data of several kinds of engineering materials from ferritic steels to austenitic stainless steels are used. These are the authors original data published in the documents of NRIM Fatigue Data Sheets. The result of 304 stainless steel has been compared with statistical analysis result by Diercks adopted in a design code. The fatigue life curves represented by the proposed parameter analysis fitted well test data in high-cycle region as well as ones in low-cycle region.

The Effect of Nitrogen Alloying on the Low Cycle Fatigue and Creep-Fatigue Interaction Behavior of 316LN Stainless Steel

2013 ◽  
Vol 794 ◽  
pp. 441-448 ◽  
Author(s):  
G.V. Prasad Reddy ◽  
R. Sandhya ◽  
M.D. Mathew ◽  
S. Sankaran
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hold Time ◽  
Cyclic Plasticity ◽  
Dynamic Strain ◽  
Cycle Fatigue ◽  
Intergranular Cracking ◽  
Creep Fatigue

Low cycle fatigue (LCF) and Creep-fatigue interaction (CFI) behavior of 316LN austenitic stainless steel alloyed with 0.07, 0.11, 0.14, .22 wt.% nitrogen is briefly discussed in this paper. The strain-life fatigue behavior of these steels is found to be dictated by not only cyclic plasticity but also by dynamic strain aging (DSA) and secondary cyclic hardening (SCH). The influence of the above phenomenon on cyclic stress response and fatigue life is evaluated in the present study. The above mentioned steels exhibited both single-and dual-slope strain-life fatigue behavior depending on the test temperatures. Concomitant dislocation substructural evolution has revealed transition in substructures from planar to cell structures justifying the change in slope. The beneficial effect of nitrogen on LCF life is observed to be maximum for 316LN with nitrogen in the range 0.11 - 0.14 wt.%, for the tests conducted over a range of temperatures (773-873 K) and at ±0.4 and 0.6 % strain amplitudes at a strain rate of 3*10-3 s-1. A decrease in the applied strain rate from 3*10-3 s-1 to 3*10-5 s-1 or increase in the test temperature from 773 to 873 K led to a peak in the LCF life at a nitrogen content of 0.07 wt.%. Similar results are obtained in CFI tests conducted with tensile hold periods of 13 and 30 minutes. Fractography studies of low strain rate and hold time tested specimens revealed extensive intergranular cracking.

Effect of Temperature and Strain Rate on Low-Cycle Fatigue Life of Bi-Sn Eutectic Alloy

2013 ◽  
Author(s):  
Takuma Sato ◽  
Yoshiharu Kariya ◽  
Kazuma Fukui
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Eutectic Alloy ◽  
Low Cycle Fatigue ◽  
Effect Of Temperature ◽  
Eutectic Alloys ◽  
Cycle Fatigue ◽  
Dominant Deformation Mechanism ◽  
Boundary Sliding ◽  
Effects Of Temperature

In this study, the effects of temperature and strain rate on low cycle fatigue life of Bi-Sn eutectic alloys have been studied. The fatigue life improves with the increasing of temperature and the decreasing of strain rate. This is a reverse phenomenon from characteristics found in general metals. As temperature increases and strain rate decreases, grin boundary sliding becomes the dominant deformation mechanism and the fatigue ductility coefficient increases, resulting in an improvement of fatigue life. To the extent of this study, dependence on temperature and strain rate can be expressed by Manson-Coffin’s law modified using Z-parameters.

Direct Strain-Controlled Variable Strain Rate Low Cycle Fatigue Testing in Simulated PWR Water

2016 ◽  
Author(s):  
Tommi Seppänen ◽  
Jouni Alhainen ◽  
Esko Arilahti ◽  
Jussi Solin
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Strain Rate ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Reference Value ◽  
Hot Water ◽  
Feedback Signal ◽  
Cycle Fatigue ◽  
Experimental Values

A tailored-for-purpose environmental fatigue testing facility was previously developed to perform direct strain-controlled tests on stainless steel in simulated PWR water. Strain in specimen mid-section is generated by the use of pneumatic bellows, and eddy current measurement is used as a feedback signal. The procedure conforms with the ASTM E 606 practice for low cycle fatigue, giving results which are directly compatible with the major NPP design codes. Past studies were compiled in the NUREG/CR-6909 report and environmental reduction factors Fen were proposed to account for fatigue life reduction in hot water as compared to a reference value in air. This database exclusively contained non-stabilized stainless steels, mainly tested under stroke control. The applicability of the stainless steel Fen factor for stabilized alloys was already challenged in past papers (PVP2013-97500, PVP2014-28465). The results presented in this paper follow the same overall trend of lower experimental values (4.12–11.46) compared to those expected according to the NUREG report (9.49–10.37). In this paper results of a dual strain rate test programme on niobium stabilized AISI 347 type stainless steel are presented and discussed in the context of the NUREG/CR-6909 Fen methodology. Special attention is paid to the effect of strain signal on fatigue life, which according to current prediction methods does not affect the value of Fen.

scholarly journals Effect of Hold Time on Low Cycle Fatigue Life of Micro Solder Joint

2008 ◽  
Vol 49 (7) ◽  
pp. 1524-1530 ◽  
Author(s):  
Yoshihiko Kanda ◽  
Yoshiharu Kariya ◽  
Yusuke Mochizuki
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Low Cycle Fatigue ◽  
Hold Time ◽  
Cycle Fatigue

Influence of Hold-Time and Temperature on the Low-Cycle Fatigue of Incoloy 800

1972 ◽  
Vol 94 (3) ◽  
pp. 930-934 ◽  
Author(s):  
C. E. Jaske ◽  
H. Mindlin ◽  
J. S. Perrin
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Compressive Strain ◽  
Hold Time ◽  
Strain Range ◽  
Cyclic Fatigue ◽  
Cycle Fatigue ◽  
Incoloy 800 ◽  
Strain Cycling

A study has been conducted to determine the low-cycle fatigue behavior of solution-annealed Incoloy 800 bar at temperatures from 800–1400 deg F. The experimental work included evaluation of specimens under both continuous, completely reversed strain cycling and under strain cycling with hold time periods at the strain limits. At 1000, 1200, and 1400 deg F, it was found that 10-min hold-times at the tensile strain limit during every cycle significantly reduced the cyclic fatigue life compared to continuous cycling. However, there was little reduction in cyclic fatigue life when 10-min hold-times were introduced at the compressive strain limits or at both the tensile and compressive limits. The ratio of hold-time cyclic fatigue life to no-hold-time cyclic fatigue life decreased as the length of hold time increased (at constant total strain range) and as the magnitude of strain range decreased (at constant hold-time length).

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