On the Research and Application of Ultrasonic Fatigue Testing Technology

2015 ◽  
Vol 664 ◽  
pp. 62-67
Author(s):  
Wen Jie Peng ◽  
Yue Wang ◽  
Huan Xue ◽  
Jia He
Keyword(s):  
Size Effect ◽  
Fatigue Test ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Smelting Process ◽  
Fatigue Properties ◽  
Frequency Effect ◽  
Cycle Fatigue ◽  
Testing Technology ◽  
Ultrasonic Fatigue

In the present paper, the characteristic and the application of ultrasonic fatigue testing technology is illuminated. The main problems i.e. the size effect, the thermal effect and frequency effect due to the high frequency are discussed. The results show that: 1. As there is a size effect, a uniform specimen size should be adopted in the very-high cycle fatigue standard and for special designed specimen the designed size should be noted along with the fatigue test results; 2.the heat generation attributes mainly to the low yield strength and the high applied stress, as a result, ultrasonic fatigue testing technology can be mainly applied to the ultra-high cycle fatigue test of high-strength steel; 3.the frequency effect is related to the crystal structure of metallic materials, however, ultrasonic fatigue testing technology can be applied to conduct the comparison of the fatigue properties of the same steel grade before and after the smelting process.

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.

Ultra-High Cycle Fatigue Behavior of DZ125 Superalloy Used in Turbine Blades

2015 ◽  
Vol 664 ◽  
pp. 96-103
Author(s):  
Yu Li Gu ◽  
Chun Hu Tao
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Turbine Blades ◽  
Frequency Effect ◽  
Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Ultra High Cycle Fatigue ◽  
Fish Eye

The high temperature ultra-high cycle fatigue (UHCF) behaviors of DZ125 superalloy used in aero-engine turbine blades were systematically studied. The results show that the fatigue fracture still occurs above 108 at the frequency of 20kHz, R=-1 and 700°C. There is a negligible frequency effect for the DZ125 superalloy, therefore, it is proposed that the ultrasonic fatigue testing could be expected as an accelerated fatigue testing method. Fatigue cracks originate from the subsurface of the specimens, where have no metallurgy defects or “fish eye” character. The crystal orientation change of the alloy is very little after fatigue.The maximum value changed for the elastic modulus of the alloy is about 30GPa after fatigue compared with that before fatigue.

scholarly journals The influential factors on very high cycle fatigue testing results

2018 ◽  
Vol 165 ◽  
pp. 20002 ◽  
Author(s):  
PENG Wen-jie ◽  
XUE Huan ◽  
GE rui ◽  
PENG zhou
Keyword(s):  
Fatigue Test ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Inclusion Size ◽  
Influential Factors ◽  
Test Results ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Very High

When the fatigue cycle is extended from high cycle (105~107) to very high cycle (107~109), the fatigue testing results will be more sensitive to the influential factors such as specimen size, specimen surface roughness and the inclusion size. The influential factors on the very high cycle fatigue testing results are investigated in the present paper. Firstly, the design and control method for ultrasonic fatigue test were introduced for several specimen shapes. The effect of the shape, size and the surface roughness of specimen on the ultrasonic fatigue test results are investigated. Meanwhile, the effect of test frequency and the size of the inclusion on the fatigue test results are also investigated. It is concluded that: 1. the test results of specimen with different shape and size differ with each other, due to the risk volume is different. 2. There is a critical roughness for the specimen, depending on the hardness of tested metallic material. A larger roughness than the critical one will lead to a premature fracture. 3. The frequency effect is obvious for the low strength steel, however, is prone to vanish for the very high strength steel. 4. The very high cycle fatigue will be more sensitive to the inclusion size as the strength increases and the S/N curve character is strongly related to the size of the inclusion.

Evaluation of Very High Cycle Fatigue Properties of β-Titanium Alloy by Using an Ultrasonic Tensile-Compressive Fatigue Testing Machine

2016 ◽  
Vol 725 ◽  
pp. 366-371 ◽  
Author(s):  
Reo Kasahara ◽  
Masato Nishikawa ◽  
Yoshinobu Shimamura ◽  
Keiichiro Tohgo ◽  
Tomoyuki Fujii
Keyword(s):  
Titanium Alloy ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fracture Morphology ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Very High

β-titanium alloy has been developed recently because β-titanium alloy has better cold workability, proof stress, and tensile strength. In order to use β-titanium alloy for automobile parts subject to cyclic loading, very high cycle fatigue properties of β-titanium alloy should be investigated. In this study, very high cycle fatigue properties of β-titanium alloy Ti-22V-4Al were evaluated by using an ultrasonic fatigue testing method, which allows us to reduce a fatigue testing period to 1/100 − 1/1000 of that by using conventional testing methods. An S-N diagram and fracture morphology of Ti-22V-4Al in the very high cycle region were investigated. Fatigue failure was observed and subsurface fracture occurred in the very high cycle region.

scholarly journals Usability of Ultrasonic Frequency Testing for Rapid Generation of High and Very High Cycle Fatigue Data

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2245
Author(s):  
Michael Fitzka ◽  
Bernd M. Schönbauer ◽  
Robert K. Rhein ◽  
Niloofar Sanaei ◽  
Shahab Zekriardehani ◽  
...  
Keyword(s):  
Strain Rate ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Reinforced Polymer ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Fibre Reinforced Polymer ◽  
Very High

Ultrasonic fatigue testing is an increasingly used method to study the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) properties of materials. Specimens are cycled at an ultrasonic frequency, which leads to a drastic reduction of testing times. This work focused on summarising the current understanding, based on literature data and original work, whether and how fatigue properties measured with ultrasonic and conventional equipment are comparable. Aluminium alloys are not strain-rate sensitive. A weaker influence of air humidity at ultrasonic frequencies may lead to prolonged lifetimes in some alloys, and tests in high humidity or distilled water can better approximate environmental conditions at low frequencies. High-strength steels are insensitive to the cycling frequency. Strain rate sensitivity of ferrite causes prolonged lifetimes in those steels that show crack initiation in the ferritic phase. Austenitic stainless steels are less prone to frequency effects. Fatigue properties of titanium alloys and nickel alloys are insensitive to testing frequency. Limited data for magnesium alloys and graphite suggest no frequency influence. Ultrasonic fatigue tests of a glass fibre-reinforced polymer delivered comparable lifetimes to servo-hydraulic tests, suggesting that high-frequency testing is, in principle, applicable to fibre-reinforced polymer composites. The use of equipment with closed-loop control of vibration amplitude and resonance frequency is strongly advised since this guarantees high accuracy and reproducibility of ultrasonic tests. Pulsed loading and appropriate cooling serve to avoid specimen heating.

Effect of Plasma Nitriding on Ultra-High Cycle Fatigue Behaviors of Ti-6Al-4V

2011 ◽  
Vol 295-297 ◽  
pp. 2386-2389 ◽  
Author(s):  
Ren Hui Tian ◽  
Qiao Lin Ouyang ◽  
Qing Yuan Wang
Keyword(s):  
High Cycle Fatigue ◽  
Plasma Nitriding ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Ultra High Cycle Fatigue ◽  
Stress Ratios

In order to investigate the effect of plasma nitriding treatment on fatigue behavior of titanium alloys, very high cycle fatigue tests were carried out for Ti-6Al-4V alloy using an ultrasonic fatigue machine under load control conditions for stress ratios of R=-1 at frequency of ƒ=20KHz. Experiment results showed that plasma nitriding treatment played the principal role in the internal fatigue crack initiation. More importantly, plasma nitriding treatment had a detrimental effect on fatigue properties of the investigated Ti-6Al-4V alloy, and the fatigue strength of material after plasma nitriding treatment appeared to be significantly reduced about 17% over the untreated material.

Very High Cycle Fatigue Testing under Spectrum Loading for Endurance Limit Structural Design

2020 ◽  
Vol 65 (1) ◽  
pp. 1-7
Author(s):  
David T. Rusk ◽  
Robert E. Taylor ◽  
Bruce A. Pregger ◽  
Luis J. Sanchez
Keyword(s):  
Fatigue Test ◽  
Test Data ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Crack Nucleation ◽  
Peak Stress ◽  
Material Behavior ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High

A program has recently concluded that generated fatigue test data for the influence of a rotorcraft main rotor blade root bending spectrum (Helix) on the crack nucleation mechanisms in 7075-T651 aluminum. High-frequency tests were performed that generated spectrum fatigue failures out to nearly 109 cycles. Fractographic examination showed a distinct change in crack nucleation from slip initiated to inclusion-initiated cracking as the spectrum peak stress level was increased. Spectrum life predictions were made using three different baseline constant-amplitude S-N curves, one using a traditional rotorcraft original equipment manufacturer fitting methodology, one using the high-cycle fatigue (HCF) portion of a strainlife curve, and one that was fitted to S-N data with test lives out to 3×108 cycles. The spectrum life prediction using the S-N curve that properly modeled material behavior in the very high cycle fatigue regime provided a good correlation to the spectrum fatigue test data. Predictions using the other S-N curves were highly conservative.

Sign in / Sign up

Export Citation Format

Share Document