A Procedure for Low Cycle Fatigue Life Prediction for Various Temperatures and Strain Rates

1990 ◽  
Vol 112 (4) ◽  
pp. 422-428 ◽  
Author(s):  
Ange Zhang ◽  
T. Bui-Quoc ◽  
R. Gomuc
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Low Frequency ◽  
Strain Range ◽  
Strain Rates ◽  
Total Strain Range ◽  
Wide Range ◽  
Experimental Values

This paper describes a procedure that permits the calculation of the fatigue life over a wide range of temperatures and strain rates. The isothermal fatigue life is expressed in terms of the total strain range by an equation previously obtained from a continuous damage concept. Additional new terms are introduced to take into account the effect of the temperature and of the strain rate. For a given material, a multiple regression analysis is carried out using some experimental results in order to evaluate the material constants involved. Once these constants are known, the life prediction can be made for other specified values of temperature and strain rate. The approach is applied to available data obtained from several stainless steels (AISI 304, 316, 348, and some SUS materials) under several combinations of temperatures and strain rates. The deviation of the calculated lives from the experimental values is reasonably acceptable. The extension of the proposed procedure to cases of cycling with a very low frequency, usually involving hold times, is examined and discussed.

Tensile and Fatigue Properties of Miniature Size Specimens of Sn-5Sb Lead-Free Solder

2016 ◽  
Vol 879 ◽  
pp. 2377-2382 ◽  
Author(s):  
Kyosuke Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Hokazono
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Phase Boundary ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Total Strain ◽  
Effect Of Temperature ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Total Strain Range

Tensile and low cycle fatigue properties of Sn-5Sb (mass%) solder were investigated with miniature size tensile specimens. The effect of temperature and strain rate on tensile properties and the effect of temperature on low cycle fatigue properties were examined. Tensile strength increases with increasing strain rate regardless of temperature investigated. For elongation, the effect of temperature on it is negligible although it slightly increases with increasing strain rate. The low cycle fatigue life of Sn-5Sb obeys by the Manson-Coffin’s equation. The effect of temperature on the fatigue life is negligible in the temperature range from 25 oC to 150 oC. In the low cycle fatigue test with a high total strain range of 4%, cracking at phase boundary mainly occurs regardless of temperature investigated. In the case of a low total strain range of 0.4%, ductile fracture mainly occurs, and cracking at phase boundary with generation of grooves also occurs at high temperature.

LOW CYCLE FATIGUE BEHAVIOR AND LIFE PREDICTION OF A CAST COBALT-BASED SUPERALLOY

2012 ◽  
Vol 06 ◽  
pp. 251-256
Author(s):  
HO-YOUNG YANG ◽  
JAE-HOON KIM ◽  
KEUN-BONG YOO
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Life Prediction ◽  
Prediction Models ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Total Strain ◽  
Cycle Fatigue ◽  
Total Strain Range ◽  
Different Temperatures

Co -base superalloys have been applied in the stationary components of gas turbine owing to their excellent high temperature properties. Low cycle fatigue data on ECY-768 reported in a companion paper were used to evaluate fatigue life prediction models. In this study, low cycle fatigue tests are performed as the variables of total strain range and temperatures. The relations between plastic and total strain energy densities and number of cycles to failure are examined in order to predict the low cycle fatigue life of Cobalt-based super alloy at different temperatures. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.

Multiaxial Low Cycle Fatigue Life Prediction at 300 °C Using Equivalent Strain Appoach

2011 ◽  
Vol 361-363 ◽  
pp. 1669-1672
Author(s):  
Wen Xiao Zhang ◽  
Guo Dong Gao ◽  
Guang Yu Mu
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Strain Range ◽  
Cyclic Fatigue ◽  
Equivalent Strain ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue

The low cycle fatigue behavior was experimentally studied with the 3-dimension notched LD8 aluminum alloy specimens at 300°C. The 3- dimension stress-strain responses of specimens were calculated by means of the program ADINA. The multiaxial fatigue life prediction was carried out according to von Mises’s equivalent theory. The results from the prediction showed that the equivalent strain range can be served as the valid mechanics for predicting multiaxial high temperature and low cyclic fatigue life.

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.

Fatigue Life Prediction Using Average Strain Range of Fatigue Process Zone

2010 ◽  
Vol 29-32 ◽  
pp. 474-478
Author(s):  
Dong Lei ◽  
Bin Kai Shi ◽  
Ge Li ◽  
Jian Hua Zhao
Keyword(s):  
Fatigue Life ◽  
Stress Concentration ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Process Zone ◽  
Strain Range ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Average Strain ◽  
Fatigue Process

In low-cycle fatigue process, plastic strain takes place at notch root vicinity fast appears induced by high stress concentration. Plastic strain makes material non-uniform and the change of distribution of local stress. The approximation to stress concentration point of Neuber’s rule is not suitable for some plastic materials in engineering practice. In this paper, the average strain of fatigue process zone was considered to substitute Neuber strain for predicting fatigue life. Prediction results indicated that average strain range of fatigue process zone is more suitable than Neuber strain range for predicting low-cycle fatigue life of LY12CZ.

A Strain Rate Ratio Approach for Assessing Creep-Fatigue Life of 63Sn-37Pb Solder Under Shear Loading

2004 ◽  
Vol 127 (4) ◽  
pp. 407-414 ◽  
Author(s):  
Yutaka Tsukada ◽  
Hideo Nishimura ◽  
Hiroki Yamamoto ◽  
Masao Sakane
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Rate Ratio ◽  
Life Prediction ◽  
Strain Range ◽  
Shear Loading ◽  
Strain Waves ◽  
Creep Fatigue ◽  
Ratio Approach ◽  
Damage Rule

This paper studies creep-fatigue life prediction under shear loading by making extensive torsion creep-fatigue experiments using four kinds of strain waves. The linear damage rule, strain range partitioning method, frequency modified fatigue life, and ductility exhaustion model were applied to the experimental data, but no methods accurately predicted the creep-fatigue life. A new method based on the strain rate ratio, which predicted the creep-fatigue life within a factor of 4 scatter band, was developed.

Low Cycle Fatigue of Alloy 617 at 850 °C and 950 °C

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
J. K. Wright ◽  
L. J. Carroll ◽  
J. A. Simpson ◽  
R. N. Wright
Keyword(s):  
Strain Rate ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Strain Range ◽  
Cyclic Hardening ◽  
Solute Drag ◽  
Cycle Fatigue ◽  
Alloy 617 ◽  
Total Strain Range ◽  
Cycles To Failure

The low cycle fatigue behavior of Alloy 617 has been evaluated at 850 °C and 950 °C, the temperature range of particular interest for the intermediate heat exchanger on a proposed high-temperature gas-cooled nuclear reactor. Cycles to failure were measured as a function of total strain range and varying strain rate. Results of the current experiments compare well with previous work reported in the literature for a similar range of temperatures and strain rate. The combined data demonstrate a Coffin–Manson relationship, although the slope of the Coffin–Manson fit is close to −1 rather than the typically reported value of −0.5. At 850 °C and a strain rate of 10−3 /s Alloy 617 deforms by a plastic flow mechanism in low cycle fatigue and exhibits some cyclic hardening. At 950 °C for strain rates of 10−3–10−5 /s, Alloy 617 deforms by a solute drag creep mechanism during low cycle fatigue and does not show significant cyclic hardening or softening. At this temperature the strain rate has little influence on the cycles to failure for the strain ranges tested.

scholarly journals Limitations of Viscoelastic Constitutive Models for Carbon-Black Reinforced Rubber in Medium Dynamic Strains and Medium Strain Rates

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 988 ◽  
Author(s):  
Francesca Carleo ◽  
Ettore Barbieri ◽  
Roly Whear ◽  
James Busfield
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Low Cycle Fatigue ◽  
Constitutive Models ◽  
Strain Range ◽  
Operating Conditions ◽  
Strain Rates ◽  
Strain And Strain Rate ◽  
Wide Range ◽  
Dynamic Strains

Modelling the viscoelastic behavior of rubber for use in component design remains a challenge. Most of the literature does not consider the typical regimes encountered by anti-vibration devices that are deformed to medium dynamic strains (0.5 to 3.5) at medium strain rates (0.5/s to 10/s). Previous studies have either focused on the behaviour at small strains and small strain rates or in fast loading conditions that result in low cycle fatigue or tearing phenomena. There is a lack of understanding of the dynamic response of natural rubber suspension components when used in real vehicle applications. This paper presents a review of popular viscoelastic nonlinear constitutive models and their ability to model the mechanical behaviour of typical elastomer materials such as Natural Rubber (NR) incorporating different PHR (Parts per Hundred Rubber, XX) of carbon black. The range of strain and strain rate are typical for the materials used in rubber suspensions when operating in severe service operating conditions, such as over rough terrain or over pot-holes. The cyclic strain is applied at different amplitudes and different strain rates in this medium strain range. Despite the availability of many models in the literature, our study reports that none of the existing models can fit the data satisfactorily over a wide range of conditions.

Investigation on Low Cycle Fatigue Life of SC Notched Specimens

2010 ◽  
Vol 97-101 ◽  
pp. 449-452
Author(s):  
Ping Zhao ◽  
Qing Hua He ◽  
Wei Li
Keyword(s):  
Fatigue Life ◽  
Stress Ratio ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Total Strain Range ◽  
Notched Specimens ◽  
Orientation Function ◽  
Fatigue Notch Factor

A low cycle fatigue life (LCF) prediction model for nickel-based single crystal (SC) is presented based on the LCF experiments of notched specimens. Fatigue notch factor is adopted to reflect the influence of notch shape on LCF. Orientation function is adopted to modify total strain range and eliminate the influence of orientation on LCF. Cycle stress ratio is adopted to reflect the influence of mean stress and cycle character on LCF. The predicted results shows that all the data are in the factor of 2.1 scatter band, which means that the model proposed in this work is reasonable.

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