Mean Strain Effect on the Cyclic Stress-Strain Behavior of Steel Structure Materials Q235

2012 ◽  
Vol 602-604 ◽  
pp. 430-434 ◽  
Author(s):  
Yi Guo ◽  
Yun Rong Luo ◽  
Qing Yuan Wang
Keyword(s):  
Low Cycle Fatigue ◽  
Steel Structure ◽  
Cyclic Hardening ◽  
Cyclic Stress ◽  
Strain Effect ◽  
Cycle Fatigue ◽  
Q235 Steel ◽  
Strain Behavior ◽  
Mean Stress Relaxation ◽  
Mean Strain

The low cycle fatigue (LCF) behavior of Q235 steel under mean strain control has been investigated. A serious of the strain controlled cyclic loading experiments with several combinations of strain amplitudes and mean strains have been performed. Significant cyclic hardening and mean stress relaxation were observed in all cases. Fractography by scanning electron microscopy (SEM) was used to determine the LCF failure mechanisms and fatigue crack propagation modes of the Q235 steel.

Cyclic Stress-Strain Behavior and Low Cycle Fatigue of Ti 6242

1990 ◽  
Vol 18 (3) ◽  
pp. 160
Author(s):  
A Wolfenden ◽  
T Bui-Quoc ◽  
R Gomuc ◽  
A Biron ◽  
HL Nguyen ◽  
...  
Keyword(s):  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Strain Behavior

Low Cycle Fatigue Behavior of Spray Formed Superalloy Rings

2011 ◽  
Vol 399-401 ◽  
pp. 1937-1941 ◽  
Author(s):  
Wen Yong Xu ◽  
Guo Qing Zhang ◽  
Zhou Li
Keyword(s):  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hysteresis Loops ◽  
Cyclic Strain ◽  
Cyclic Hardening ◽  
Cyclic Stress ◽  
Total Strain ◽  
Total Strain Amplitude ◽  
Cycle Fatigue

Low cycle fatigue behavior of spray formed superalloy GH738 at 650°C has been investigated under fully reversed total strain-controlled mode. When strain amplitude (Δεt/2) is between 0.32% and 0.4%, cyclic stress response is stable under fully reversed constant total strain amplitude. The stabilized hysteresis loops narrowing sharply to a straight line indicates that the alloy exhibits typical elastic strain. The crack initiates single site from the surface. When strain amplitude is between 0.6% and 1.0%, cyclic hardening is observed until fracture. The tendency for hardening is found to increase with strain amplitude. The hyperesis loops expand gradually, which indicates that plastic deformation happens during cyclic deformation process. The crack initiates multi-sites from the surface. The cyclic strain-stress relationship of spray formed GH738 at 650°C can be illustrated by Δσ/2 =2017(Δεp/2)0.1489.The total strain-life function can expressed by Δεt/2=0.0071(2Nf)-0.0781+0.0647(2Nf) )-0.4914.

Cyclic stress–strain behavior and low cycle fatigue life of cast A356 alloys

2011 ◽  
Vol 33 (12) ◽  
pp. 1600-1607 ◽  
Author(s):  
M.S. Song ◽  
Y.Y. Kong ◽  
M.W. Ran ◽  
Y.C. She
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Strain Behavior

Cyclic Stress-Strain Behavior and Low-Cycle Fatigue of Ti 6-4 at 260°C

1992 ◽  
Vol 114 (4) ◽  
pp. 390-398 ◽  
Author(s):  
T. Bui-Quoc ◽  
R. Gomuc ◽  
A. Biron
Keyword(s):  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Strain Curve ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Strain Behavior ◽  
Show Evidence ◽  
Strain Cycling

Low-cycle fatigue tests on Ti 6-4 (Ti-6Al-4V) have been carried out at 260°C under strain-controlled conditions with constant strain amplitude and increasing multistep strain levels. The results of constant strain amplitude tests were used to establish the fatigue diagram whereas the multistep tests were examined to assess the cyclic stress-strain behavior in comparison with the conventional stress-strain curve. Most of the tests were carried out under zero-to-tension conditions in the intermediatecycle range (Nf ≃ 3 x 103 to 105 cycles). The effect of prior strain cycling on the tensile properties was also investigated. The experimental data is discussed together with theoretical evaluations. In addition, microstructural examinations of the rupture surfaces have been made to show evidence on the type of crack initiation sites and on the crack propagation modes at different strain levels.

Stress-Strain Behavior of Inconel 718 During Low Cycle Fatigue

1982 ◽  
Vol 104 (3) ◽  
pp. 186-191 ◽  
Author(s):  
T. S. Cook
Keyword(s):  
Inconel 718 ◽  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Strain Behavior ◽  
Varied Temperature ◽  
The Mean

In the development of better methods of assessing damage accumulation, one of the requirements is an understanding of the cyclic constitutive behavior of the material. It is known that the cyclic stress-strain behavior is affected by temperature and possibly Rε ratio (εmin/εmax) and that the properties change as cycles are accumulated. This report presents some results, particularly the development of a mean stress in the material, obtained during low cycle fatigue tests of Inconel 718. The tests varied temperature and Rε ratio to determine their effects on the cyclic constitutive relation. Changes in the cyclic stress-strain behavior as a function of cycles were also examined. It was possible to relate the mean stress to either the total or plastic strain ranges for all temperatures. There was sufficient scatter in the data to prevent an unambiguous interpretation of the effect of Rε ratio on the mean stress, however.

Low-cycle fatigue and cyclic stress-strain behavior of incoloy 800

1972 ◽  
Vol 3 (6) ◽  
pp. 1633-1637 ◽  
Author(s):  
J. B. Conway ◽  
J. T. Berling ◽  
R. H. Stentz
Keyword(s):  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Strain Behavior ◽  
Incoloy 800
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