Very High Cycle Fatigue of Cast Aluminum Alloys under Variable Humidity Levels

2015 ◽  
Vol 8 (2) ◽  
pp. 444-449 ◽  
Author(s):  
Wenkai Li ◽  
Haitao Cui ◽  
Weidong Wen ◽  
Xuming Su ◽  
Carlos Engler-Pinto
Keyword(s):  
Aluminum Alloys ◽  
High Cycle Fatigue ◽  
Cycle Fatigue ◽  
Cast Aluminum ◽  
Very High Cycle Fatigue ◽  
Cast Aluminum Alloys ◽  
Very High

High and very high cycle fatigue failure mechanisms in selective laser melted aluminum alloys

2017 ◽  
Vol 32 (23) ◽  
pp. 4296-4304 ◽  
Author(s):  
Shafaqat Siddique ◽  
Mustafa Awd ◽  
Jochen Tenkamp ◽  
Frank Walther
Keyword(s):  
Aluminum Alloys ◽  
Fatigue Failure ◽  
High Cycle Fatigue ◽  
Failure Mechanisms ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Image Position ◽  
Very High

Abstract

High Cycle Fatigue of Cast Aluminum Alloys at Ultrasonic Frequency

2006 ◽  
Author(s):  
C.C. Engler-Pinto ◽  
R.J. Frisch ◽  
J.V. Lasecki ◽  
J.E. Allison ◽  
X. Zhu ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
High Cycle Fatigue ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Cast Aluminum ◽  
Cast Aluminum Alloys

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.

scholarly journals On the determination of the bending fatigue strength in and above the very high cycle fatigue regime of shot-peened gears

2021 ◽  
Author(s):  
D. Fuchs ◽  
S. Schurer ◽  
T. Tobie ◽  
K. Stahl
Keyword(s):  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Load Carrying Capacity ◽  
Cycle Fatigue ◽  
Bending Fatigue ◽  
Very High Cycle Fatigue ◽  
Bending Load ◽  
Load Carrying ◽  
Bending Fatigue Strength ◽  
Very High

AbstractDemands on modern gearboxes are constantly increasing, for example to comply with lightweight design goals or new CO2 thresholds. Normally, to increase performance requires making gearboxes and powertrains more robust. However, this increases the weight of a standard gearbox. The two trends therefore seem contradictory. To satisfy both of these goals, gears in gearboxes can be shot-peened to introduce high compressive residual stresses and improve their bending fatigue strength. To determine a gear’s tooth root bending fatigue strength, experiments are conducted up to a defined number of load cycles in the high cycle fatigue range. However, investigations of shot-peened gears have revealed tooth root fracture damage initiated at non-metallic inclusions in and above the very high cycle fatigue range. This means that a further reduction in bending load carrying capacity has to be expected at higher load cycles, something which is not covered under current standard testing conditions. The question is whether there is a significant decrease in the bending load carrying capacity and, also, if pulsating tests conducted at higher load cycles—or even tests on the FZG back-to-back test rig—are necessary to determine a proper endurance fatigue limit for shot-peened gears. This paper examines these questions.

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