Cyclic Stress-Strain Behavior and Low Cycle Fatigue Life of AA6061 Aluminum Alloy

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.

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Cyclic stress-strain behavior and low-cycle fatigue of Ti 6242Thang, B.-Q., Gomuc, R. Biron, A., Nguyen, H.L. and Tadros, R. ASTM J. Test. Eval. May 1990 18, (3), 160–171

International Journal of Fatigue ◽

10.1016/0142-1123(91)90175-x ◽

1991 ◽

Vol 13 (1) ◽

pp. 89-89

Keyword(s):

Low Cycle Fatigue ◽

Cyclic Stress ◽

Cycle Fatigue ◽

Stress Strain ◽

Strain Behavior

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Cyclic Stress-Strain Response and Low-Cycle Fatigue Life in Metallic Materials

JSME international journal Ser 1 Solid mechanics strength of materials ◽

10.1299/jsmea1988.33.1_13 ◽

1990 ◽

Vol 33 (1) ◽

pp. 13-25 ◽

Cited By ~ 2

Author(s):

Kenji HATANAKA

Keyword(s):

Fatigue Life ◽

Low Cycle Fatigue ◽

Cyclic Stress ◽

Strain Response ◽

Metallic Materials ◽

Cycle Fatigue ◽

Stress Strain

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Cyclic stress-strain behavior and low-cycle fatigue of Ti 6-4 at 260 °C

International Journal of Fatigue ◽

10.1016/0142-1123(93)90285-x ◽

1993 ◽

Vol 15 (6) ◽

pp. 528

Keyword(s):

Low Cycle Fatigue ◽

Cyclic Stress ◽

Cycle Fatigue ◽

Stress Strain ◽

Strain Behavior

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

Journal of Engineering Materials and Technology ◽

10.1115/1.2904190 ◽

1992 ◽

Vol 114 (4) ◽

pp. 390-398 ◽

Cited By ~ 2

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.

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Stress-Strain Behavior of Inconel 718 During Low Cycle Fatigue

Journal of Engineering Materials and Technology ◽

10.1115/1.3225063 ◽

1982 ◽

Vol 104 (3) ◽

pp. 186-191 ◽

Cited By ~ 7

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.

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