Low – Cost, Accelerated High-Cycle Fatigue Testing by Resonant Dwell

2012 ◽  
Author(s):  
P. W. Whaley ◽  
L. A. Killingsworth ◽  
T. D. Bow
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Low Cost ◽  
Fatigue Properties ◽  
Test Machine ◽  
Cycle Fatigue ◽  
New Materials ◽  
Hydraulic Test ◽  
Electrodynamic Shaker

Characterization of the fatigue properties of new materials using conventional empirical procedures will be very expensive and time-consuming because of the need for sufficient fatigue life data, especially in the high cycle fatigue (HCF) region. Fatigue specimens tested at 30 Hz require over nine hours to accumulate 106 cycles for each fatigue data point. Resonant-dwell double-cantilever beam specimens resonating at approximately 260 Hz accumulate 106 cycles in about an hour. This paper describes low–cost, accelerated HCF fatigue testing using resonant – dwell specimens and a small, inexpensive electrodynamic shaker. Using this method, HCF data needed for characterizing the fatigue properties of new materials can be collected about nine times faster than a servo–hydraulic test machine operating at 30 Hz.

Analysis on High Cycle Fatigue Properties and Fatigue Damage Evolution of TC25 Titanium Alloy

2016 ◽  
Vol 697 ◽  
pp. 658-663
Author(s):  
Rong Guo Zhao ◽  
Ya Feng Liu ◽  
Yong Zhou Jiang ◽  
Xi Yan Luo ◽  
Qi Bang Li ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Strain Hardening ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
High Cycle Fatigue ◽  
Damage Model ◽  
Fatigue Properties ◽  
Test Machine ◽  
Cycle Fatigue

The high cycle fatigue tests for smooth specimens of TC25 titanium alloy under different stress ratios are carried out on a MTS 809 Material Test Machine at a given maximum stress level of 917MPa at ambient temperature, the high cycle fatigue lifetimes for such alloy are measured, and the effects of stress amplitude and mean stress on high cycle fatigue life are analyzed. The initial resistance is measured at the two ends of smooth specimen of TC25 titanium alloy, every a certain cycles, the fatigue test is interrupted, and the current resistance values at various fatigue cycles are measured. The ratio of resistance change is adopted to characterize the fatigue damage evolution in TC25 titanium alloy, and a modified Chaboche damage model is applied to derive the fatigue damage evolution equation. The results show that the theoretical calculated values agree well with the test data, which indicates that the modified Chaboche damage model can precisely describe the accumulated damage in TC25 titanium alloy at high cycle fatigue under unaxial loading. Finally, the high cycle fatigue lifetimes for TC25 titanium alloy specimens at different strain hardening rates are tested at a given stress ratio of 0.1, the effect of strain hardening on fatigue life is investigated based on a microstructure analysis on TC25 titanium alloy, and an expression between fatigue life and strain hardening rate is derived

Verification of the Fatigue Test Method Applied with the Use of Mini Specimen

2014 ◽  
Vol 598 ◽  
pp. 243-248 ◽  
Author(s):  
Tomasz Tomaszewski ◽  
Janusz Sempruch
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Test ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Construction Material ◽  
Test Method ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Testing Methodology ◽  
Standard Specimens

In special situations the fatigue properties of the construction material can be determined using non-standard specimens, for example smaller than the normative ones (the so-called mini specimens). The research presented was made for the aluminum alloy based on the high-cycle fatigue testing methodology. The verification was made by breaking down the results with own tests which involved the use of standard specimens and stands as well as with the literature reports.

scholarly journals Effects of Specimen Size and Welded Joints on the Very High Cycle Fatigue Properties of Compressor Blade Steel KMN-I

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1244
Author(s):  
Pengfei Wang ◽  
Weiqiang Wang ◽  
Ming Zhang ◽  
Qiwen Zhou ◽  
Zengliang Gao
Keyword(s):  
Welded Joints ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Specimen Size ◽  
Compressor Blade ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High ◽  
Blade Steel

The effects of specimen size and welded joints on the very high cycle fatigue properties of compressor blade steel KMN-I were studied by ultrasonic fatigue testing. It was found that the S-N curve of large specimens had a slow decline above 107 cycles, and fatigue failure still occurred in the very high cycle regime (>107 cycles), while the very high cycle fatigue characteristics of welded specimens was less obvious, and the fatigue limit was observed. Metallographic observation and SEM analysis were carried out on the fracture of the specimens. The results showed that surface fractures were mostly observed in the large specimens, and only a small number of cracks initiated from non-metallic inclusions above 107 cycles. The cracks of welded specimens initiated from the surface below 107 cycles and initiated from the internal matrix above 107 cycles. In addition, the formation mechanism of GBF (granular bright facet) was analyzed by the “dispersive decohesion of spherical carbide” theory, and the fatigue strength and fatigue life were predicted, which was consistent with the experimental results.

scholarly journals Very High Cycle Fatigue Properties of Carburized Steel by Ultrasonic Torsional Fatigue Testing

2010 ◽  
Vol 59 (12) ◽  
pp. 938-943 ◽  
Author(s):  
Yoshinobu SHIMAMURA ◽  
Koichiro NARITA ◽  
Hitoshi ISHII ◽  
Keiichiro TOHGO ◽  
Tomoyuki FUJII ◽  
...  
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Carburized Steel ◽  
Torsional Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High

scholarly journals Influence of structure sensitising of the AlSi 316Ti austenitic stainless steel on the ultra-high cycle fatigue properties

2018 ◽  
Vol 157 ◽  
pp. 05011 ◽  
Author(s):  
Michal Jambor ◽  
František Nový ◽  
Otakar Bokůvka ◽  
Libor Trško ◽  
Monika Oravcová
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Structural Changes ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Fatigue Testing ◽  
Engineering Application ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Ultra High Cycle Fatigue

Austenitic stainless steels are the wide-spread materials, used mainly in the power industry. In that kind of engineering application, structural parts of rotating elements reach during their lifetime very high numbers of loading cycles, exceeding 107 numbers of cycles. With regard to this fact, the data of ultra-high cycle fatigue properties are needed to be used in the qualified design. Increasing demands on the efficiency cause the increase of the operating temperature, and exposition of these materials to the elevated temperatures can cause some important structural changes, which result in the sensitising of the structure. In this study authors present their own experimental results about fatigue properties of AISI 316Ti austenitic stainless steel after sensitising, in the ultra-high cycle region (Nf = 106 ~ Nf = 3×109 cycles). Fatigue tests were carried out using ultrasonic fatigue testing device with frequency f = 20 kHz at the coefficient of cycle asymmetry R = -1, and temperature T = 20±5°C. In the ultra-high cycle region was observed the continuous decrease of the fatigue properties of the AISI 316Ti, and there was recorded the negative effect of the sensitising on the ultra-high cycle fatigue properties of the AISI 316Ti.

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