A distribution model of ultra-high cycle fatigue property based on crack density for braided CFRP

2021 ◽  
Vol 256 ◽  
pp. 113037
Author(s):  
Tao Wu ◽  
Weixing Yao ◽  
Chao Xu
Keyword(s):  
High Cycle Fatigue ◽  
Crack Density ◽  
Fatigue Property ◽  
Distribution Model ◽  
Cycle Fatigue ◽  
Ultra High Cycle Fatigue

Experimental Study on Ultra-High Cycle Fatigue Property of Q345 Welded Joint

2012 ◽  
Vol 538-541 ◽  
pp. 1488-1491 ◽  
Author(s):  
Xiao Zhao ◽  
Jian Jun Zhao
Keyword(s):  
Welded Joints ◽  
High Cycle Fatigue ◽  
Welded Joint ◽  
Fatigue Testing ◽  
Experimental Studies ◽  
Base Material ◽  
Fatigue Property ◽  
Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Ultra High Cycle Fatigue

The present paper deals with experimental studies on the ultra-high cycle fatigue property of Q345 bridge steel. Using the ultrasonic fatigue testing technique, specimens of Q345 welded joint with hourglass shape were designed using an analytical method combining with the finite element method and then fatigue tested in air at room temperature under fully reversed cyclic loading conditions (R=-1). The results show that the S-N curves of welded joints and relative base material specimens show continuously decreasing tendency in the very high cycle regime (105-109 cycles). Fatigue property of welded joint is much lower than that of base material and the fatigue strength of welded joint is only 45.0% of base material. Fracture can still occur on welded joints beyond 5 106 cycles, which indicates the fatigue limit defined at lifetime of 5 106 cycles cannot guarantee a safe design.

Research on Ultra-High Cycle Fatigue Property of 45 Steel

2011 ◽  
Vol 295-297 ◽  
pp. 1911-1914
Author(s):  
Ling Ling Jin ◽  
Cai Yan Deng ◽  
Dong Po Wang ◽  
Rui Ying Tian
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Property ◽  
Sem Analysis ◽  
Test Results ◽  
Cycle Fatigue ◽  
Welded Structure ◽  
Ultrasonic Fatigue ◽  
Long Life ◽  
Ultra High Cycle Fatigue

Fatigue property of 45 steel was studied in this paper with the method of ultrasonic fatigue testing, and SEM was used to analyze microscopic characteristics of the fatigue fracture. Fatigue test results show that: S-N curves descend continuously after 108 cycles, there is no fatigue limit as the traditional fatigue conception describes. Therefore, it is very dangerous to design welded structure working in the ultra-high cycle interval with the fatigue strength corresponding to 5×106 cycles. In the super-long life range, the fatigue property of welded joints is worse than the base metal. SEM analysis shows that: fatigue crack mainly initiates from the defects in the surface or sub-surface.

Ultra-high cycle fatigue property of a multiphase steel microalloyed with niobium

2018 ◽  
Vol 718 ◽  
pp. 1-8 ◽  
Author(s):  
P. Zhao ◽  
Z. Liu ◽  
F. Du ◽  
R.D.K. Misra ◽  
C. Zhang ◽  
...  
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Property ◽  
Cycle Fatigue ◽  
Ultra High Cycle Fatigue ◽  
Multiphase Steel

scholarly journals Untersuchungskonzept zum Einfluss hoher Dehnraten auf die Zahnfußtragfähigkeit

2021 ◽  
Author(s):  
Moritz Trippe ◽  
Johannes Lövenich ◽  
Oscar Malinowski ◽  
Christian Brecher ◽  
Jens Brimmers ◽  
...  
Keyword(s):  
High Cycle Fatigue ◽  
Cycle Fatigue ◽  
Ultra High Cycle Fatigue

ZusammenfassungDer Einsatz von Getrieben in elektrifizierten Antriebssträngen und Flugzeugturbinen führt zu höheren Betriebsdrehzahlen und einer höheren Anzahl von Lastwechseln. Lastwechselzahlen von N > 107 im Ultra High Cycle Fatigue (UHCF) Bereich bewirken eine Abnahme der Dauerfestigkeit von Einsatzstählen. Außerdem steigt mit zunehmender Drehzahl die Dehnrate im Zahnfuß, was ebenfalls einen Einfluss auf die Dauerfestigkeit hat. Aufgrund der geringen Drehzahlen konventioneller Verspannungsprüfstände ist eine Untersuchung der Dehnrateneffekte heute nicht möglich. Darüber hinaus ist die Untersuchung des UHCF-Bereichs wegen der langen Prüfzeiten unwirtschaftlich.Ziel des Berichts ist ein Prüfstandskonzept zur Untersuchung des Einflusses höherer Dehnraten auf die Zahnfußtragfähigkeit von Zahnrädern bei hohen Drehzahlen. Zunächst werden die Leistungsanforderungen an das neue Prüfstandskonzept abgeleitet. Basierend auf diesen Anforderungen wird das Prüfgetriebe unter Verwendung der Norm ISO 6336 ausgelegt. Die Auslegung wird mit einer FE-basierten Zahnkontaktanalyse verifiziert und die erreichbaren Dehnraten im Betrieb analysiert. Abschließend wird das Prüfstandskonzept hinsichtlich der Lastaufbringung, des Lagerkonzepts, des Schmierungskonzepts und der möglichen Schadenserkennung vorgestellt. Der Prüfstand bietet die Möglichkeit, höhere Dehnraten zu untersuchen. Zusätzlich kann der UHCF-Bereich von Getrieben effizienter untersucht werden.

The High Cycle Fatigue Property of Mg-Gd-Y-Zn-Mn Alloy Enhanced by LPSO Phase

2021 ◽  
pp. 130367
Author(s):  
Chen Su ◽  
Jingfeng Wang ◽  
Linjie Zeng ◽  
Hao Hu ◽  
Shijie Liu
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Property ◽  
Cycle Fatigue ◽  
Lpso Phase

On the critical inclusion size of high strength steels under ultra-high cycle fatigue

2006 ◽  
Vol 427 (1-2) ◽  
pp. 167-174 ◽  
Author(s):  
Z.G. Yang ◽  
J.M. Zhang ◽  
S.X. Li ◽  
G.Y. Li ◽  
Q.Y. Wang ◽  
...  
Keyword(s):  
High Cycle Fatigue ◽  
High Strength Steels ◽  
High Strength ◽  
Inclusion Size ◽  
Cycle Fatigue ◽  
Ultra High Cycle Fatigue

A New Modified Contrast Method for Life Prediction in Combined Cycle Fatigue Test

2017 ◽  
Author(s):  
Lei Han ◽  
Cao Chen ◽  
Xiaoyong Zhang ◽  
Xiaojun Yan
Keyword(s):  
Turbine Blade ◽  
High Cycle Fatigue ◽  
Aerodynamic Force ◽  
Low Cycle Fatigue ◽  
Fracture Morphology ◽  
Combined Cycle ◽  
Full Scale ◽  
Cycle Fatigue ◽  
Contrast Method ◽  
Ultra High Cycle Fatigue

The combined high and low cycle fatigue (CCF) test on full scale turbine blade in the laboratory is an important method to evaluate the life. In fact, the low cycle fatigue which is usually caused by the centrifugal force can be confirmed easily. While, the high cycle fatigue which is usually caused by the vibration and aerodynamic force is often hard to determine. So the previous scholar has proposed the contrast method to determine the high cycle load in the field. This method utilizes the new and used blades to determine the high cycle within certain limits. While it can’t be applied effectively in the whole life range with the low cycle-high cycle-ultra high cycle fatigue theory raised. So this paper put forward the modified contrast method to realize the optimization. Firstly, the CCF tests are carried out on the turbine blade systematically. Then, the CCF damage properties, including the crack propagation, the fracture morphology and the dynamic characteristic are analyzed. Lastly, the new modified contrast method is proposed with the new coordinate axes, new fitting criterions and amend method. Through comparisons we conclude that: the new method is slightly complicated, but the evaluate precision has significantly increased. So it could be used to deal with data for CCF tests on full scale turbine blade in the future.

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.

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