Correlation between cyclic strain range and low-cycle fatigue life of metals

1965 ◽  
Vol 4 (3) ◽  
pp. 303
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Cyclic Strain ◽  
Cycle Fatigue

Cyclic Plastic Deformation of a Circular Plate With Work Hardening

1984 ◽  
Vol 106 (4) ◽  
pp. 336-341
Author(s):  
R. Winter
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Nonlinear Behavior ◽  
Strain Curve ◽  
Strain Range ◽  
Cyclic Strain ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Element Analysis

An experimental and theoretical study was performed of the nonlinear behavior of a simply supported flat circular aluminum plate under reversed cyclic central load. The application is for the analysis of cyclic stress and strain of structural components in the plastic range for predicting low-cycle fatigue life. The main purpose was to determine the relative accuracy of an elastic-plastic large deformation finite element analysis when the material properties input data are derived from monotonic (noncyclic) stress-strain curves versus that derived from cyclic stress-strain curves. The results showed that large errors could be induced in the theoretical prediction of cyclic strain range when using the monotonic stress-strain curve, which could lead to large errors in predicting low-cycle fatigue life. The use of cyclic stress-strain curves, according to the model developed by Morrow, et al., proved to be accurate and convenient.

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.

Assessment of low-cycle fatigue life of Sn-3.5mass%Ag-X (X=Bi or Cu) alloy by strain range partitioning approach

2001 ◽  
Vol 30 (9) ◽  
pp. 1184-1189 ◽  
Author(s):  
Yoshiharu Kariya ◽  
Tomoo Morihata ◽  
Eisaku Hazawa ◽  
Masahisa Otsuka
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Cycle Fatigue ◽  
Cu Alloy

Low-Cycle Fatigue Reliability Evaluation for Lead-Free Solders in Vehicle Electronics Devices

2007 ◽  
Author(s):  
Qiang Yu ◽  
Tadahiro Shibutani ◽  
Akifumi Tanaka ◽  
Takahiro Koyama ◽  
Masaki Shiratori
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Reliability Evaluation ◽  
Lead Free ◽  
Generation Process ◽  
Lead Free Solder ◽  
Cycle Fatigue ◽  
Free Solder

The changeover from eutectic Sn-Pb solder to lead-free solder (Sn-Ag-Cu) has been driven by environmental concerns in the last few years. In this study, in order to obtain the low-cycle fatigue characteristic of Sn-Ag-Cu lead-free solder joints, an isothermal mechanical fatigue test with a large strain range, which can clarify the crack generation process and shorten the examination time, was carried out. FEM analysis was also performed in order to evaluate the relationship between the inelastic strain range and the low-cycle fatigue life. As a result, compared with fatigue life longer than 1000 cycles, the scatter of the fatigue cycles from 100 to several hundred cycles becomes larger. So, it seems that it is necessary to carefully evaluate the low-cycle fatigue life in the reliability evaluation. Moreover, in large chip components, not only crack initiation, but also crack propagation, affects the failure life. Thus, the crack path was simulated and the failure cycle of the large chip was evaluated based on Miner’s rule, and reliability of including the fatigue crack propagation can be evaluated by the analytical approach.

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.

Improvement of Thermomechanical Fatigue Life in Nitrogen Alloyed 316 Stainless Steel

2005 ◽  
Vol 475-479 ◽  
pp. 1429-1432 ◽  
Author(s):  
Dae Whan Kim ◽  
Chang Hee Han ◽  
Woo Seog Ryu
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Temperature Change ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Thermomechanical Fatigue ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Phase Condition ◽  
Higher Temperature

Fatigue tests of type 316 and 316LN stainless steel were conducted at RT and 600ı, 0.8~1.5% strain range for low cycle fatigue (LCF), 300~600ı, 0% strain range for thermal fatigue (TF) and 300~600ı, 2% strain range, in-phase or out-of-phase for thermomechanical fatigue (TMF). LCF, TF, and TMF lives were increased but saturation stresses were decreased with the addition of nitrogen. The higher temperature was the lower TF life at a same temperature change. The minimum temperature change for TF failure was more than 100ı. TMF life was higher at inphase condition than at out-of-phase condition. Fracture mode was transgranular for LCF and outof- phase of TMF and almost transgranular and small intergranular for TF and in-phase TMF.

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.

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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