Cyclic creep-type fracture and fatigue-type fracture in the constant-load low cycle fatigue tests

1974 ◽  
Vol 16 (7) ◽  
pp. 433-447 ◽  
Author(s):  
Eiryo Shiratori ◽  
Yoichi Obataya
Keyword(s):  
Low Cycle Fatigue ◽  
Cyclic Creep ◽  
Constant Load ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Type Fracture

scholarly journals Durability of MAR-247 and IN-713C Nickel Superalloys under Cyclic Creep Conditions

2015 ◽  
Vol 15 (4) ◽  
pp. 17-20
Author(s):  
M. Cieśla ◽  
F. Binczyk ◽  
G. Junak ◽  
M. Mańka ◽  
P. Gradoń
Keyword(s):  
Heat Treatment ◽  
Low Cycle Fatigue ◽  
Solution Treatment ◽  
Cyclic Creep ◽  
Constant Load ◽  
Creep Process ◽  
Cycle Fatigue ◽  
Subsequent Aging ◽  
Fine Grained ◽  
Test Conditions

Abstract Paper presents the assessment of impact of heat treatment on durability in low-cycle fatigue conditions (under constant load) in castings made using post-production scrap of MAR-247 and IN-713C superalloys. Castings were obtained using modification and filtration methods. Additionally, casting made of MAR-247 were subjected to heat treatment consisting of solution treatment and subsequent aging. During low-cycle fatigue test the cyclic creep process were observed. It was demonstrated that the fine-grained samples have significantly higher durability in test conditions and , at the same time, lower values of plastic deformation to rupture Δϵpl. It has been also proven that durability of fine-grained MAR-247 samples can be further raised by about 60% using aforementioned heat treatment.

Low Cycle Fatigue Behaviors of TI-6AL-4V Alloy Controlled by Strain and Stress

2012 ◽  
Vol 525-526 ◽  
pp. 441-444
Author(s):  
Rui Feng Wang ◽  
You Tang Li ◽  
Hu Ping An
Keyword(s):  
Stress Ratio ◽  
Low Cycle Fatigue ◽  
Cyclic Strain ◽  
Cyclic Creep ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Compressive Stresses ◽  
Initial Stage ◽  
Main Factor

The low cycle fatigue behaviors of TI-6AL-4V alloy controlled by strain were investigated by experiment. The fatigue tests were performed at room temperature, and cyclic strain and stress ratio are 0.1 with triangle load wave. The results show that TI-6AL-4V alloy is soften rapidly under the cyclic tensile stresses and it is harden rapidly under the cyclic compressive stresses during the initial-stage of strain controlled fatigue, and the rates of cyclic soften and cyclic harden are decreased with the fatigue progress. The soften rate is related to the cyclic strain but little to the cyclic stress during the overall fatigue progress. The change of cyclic stress is related to the macro friction stresses. The results of experiment show that obvious cyclic creep occurs under the stress controlled low cycle fatigue conditions, and the magnitude of cyclic creep strain is related to the maximum cyclic stress. The softening of tensile friction stresses is the main factor of cyclic creep.

Installation for high-temperature cyclic creep and low-cycle fatigue tests

1982 ◽  
Vol 14 (1) ◽  
pp. 130-133
Author(s):  
V. V. Osasyuk ◽  
Yu. A. Kuzema ◽  
V. D. Man'ko
Keyword(s):  
High Temperature ◽  
Low Cycle Fatigue ◽  
Cyclic Creep ◽  
Fatigue Tests ◽  
Cycle Fatigue

Creep and Low Cycle Fatigue Characterisation of IN718 TIG Butt-Welds at 620°C

2010 ◽  
Vol 636-637 ◽  
pp. 1504-1510
Author(s):  
D.W.J. Tanner ◽  
A.A. Becker ◽  
Thomas H. Hyde
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Failure Time ◽  
Low Cycle Fatigue ◽  
Constant Load ◽  
Fatigue Tests ◽  
Inert Gas ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
High Temperature Fatigue

The testing setups, results and analysis of constant load creep and low-cycle high temperature fatigue tests of tungsten inert gas (TIG) butt-welded, thin-section INCONEL 718 (IN718) specimens are presented. The main objectives were to determine the effect the welds have on failure time and analyse any differences in their failure behaviour. It was found that although welded IN718 may exhibit comparatively little loss of tensile strength, its ductility and creep and high temperature fatigue properties are severely compromised due to its changed microstructure.

A machine for cyclic creep and low-cycle fatigue tests in the complex stressed state in a broad temperature range

1987 ◽  
Vol 19 (2) ◽  
pp. 274-277 ◽  
Author(s):  
O. K. Shkodzinskii ◽  
F. F. Giginyak ◽  
V. V. Bashta ◽  
M. V. Storchak ◽  
N. V. Stepanenko
Keyword(s):  
Stressed State ◽  
Low Cycle Fatigue ◽  
Cyclic Creep ◽  
Fatigue Tests ◽  
Broad Temperature Range ◽  
Complex Stressed State ◽  
Cycle Fatigue ◽  
Temperature Range

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Cumulative acoustic emission energy for damage detection in composites reinforced by carbon fibers within low-cycle fatigue regime at various displacement amplitudes and rates

2021 ◽  
pp. 096739112098570
Author(s):  
Mohammad Azadi ◽  
Mohsen Alizadeh ◽  
Seyed Mohammad Jafari ◽  
Amin Farrokhabadi
Keyword(s):  
Acoustic Emission ◽  
Carbon Fibers ◽  
Polymer Matrix Composites ◽  
Low Cycle Fatigue ◽  
Energy Parameter ◽  
Fatigue Tests ◽  
Matrix Cracking ◽  
Matrix Composites ◽  
Cycle Fatigue ◽  
Cumulative Energy

In the present article, acoustic emission signals were utilized to predict the damage in polymer matrix composites, reinforced by carbon fibers, in the low-cycle fatigue regime. Displacement-controlled fatigue tests were performed on open-hole samples, under different conditions, at various displacement amplitudes of 5.5, 6.0, 6.5 and 7.0 mm and also under various displacement rates of 25, 50, 100 and 200 mm/min. After acquiring acoustic emission signals during cycles, two characteristic parameters were used, including the energy and the cumulative energy. Obtained results implied that the energy parameter of acoustic emission signals could be used only for the macroscopic damage, occurring at more than 65% of normalized fatigue cycles under different test conditions. However, the cumulative energy could properly predict both microscopic and macroscopic defects, at least two failure types, including matrix cracking at first cycles and the fiber breakage at last cycles. Besides, scanning electron microscopy images proved initially such claims under all loading conditions.

Low-Cycle Fatigue Behaviour of Gas Turbine Alloys

1974 ◽  
Vol 188 (1) ◽  
pp. 321-328 ◽  
Author(s):  
W. J. Evans ◽  
G. P. Tilly
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
High Stress ◽  
Cyclic Creep ◽  
Fatigue Curve ◽  
Fatigue Behaviour ◽  
Material Surface ◽  
Tension Stress ◽  
Cycle Fatigue ◽  
Stress Tests

The low-cycle fatigue characteristics of an 11 per cent chromium steel, two nickel alloys and two titanium alloys have been studied in the range 20° to 500°C. For repeated-tension stress tests on all the materials, there was a sharp break in the stress-endurance curve between 103 and 104 cycles. The high stress failures were attributed to cyclic creep contributing to the development of internal cavities. At lower stresses, failures occurred through the growth of fatigue cracks initiated at the material surface. The whole fatigue curve could be represented by an expression developed from linear damage assumptions. Data for different temperatures and types of stress concentration were correlated by expressing stress as a fraction of the static strength. Repeated-tensile strain cycling data were represented on a stress-endurance diagram and it was shown that they correlated with push-pull stress cycles at high stresses and repeated-tension at low stresses. In general, the compressive phase tended to accentuate cyclic creep so that ductile failures occurred at proportionally lower stresses. Changes in frequency from 1 to 100 cycle/min were shown to have no significant effect on low-cycle fatigue behaviour.

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