Multiscale study of fracture in aluminum-magnesium alloy under fatigue and dynamic loading
Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 34
Abstract
In this paper we investigated the influence of consecutive dynamic and gigacycle fatigue loads on the lifetime of aluminum-magnesium alloy AlMg6. Preloading of samples was achieved during dynamic tensile tests in the split-Hopkinson bar device. Fatigue tests were conducted on Shimadzu USF-2000 ultrasonic fatigue testing machine. This machine provides 109-1010 loading cycles with the amplitude from 1 to several dozens of microns and frequency of 20 kHz, which reduces dramatically the testing time in the comparison to the classical fatigue testing machines. The New-View 5010 interferometer–profiler of high structural resolution (resolution of 0.1 nm) was used for qualitative fracture surface analysis, which provided the data allowing us to find correlation between mechanical properties and scale-invariant characteristics of damage induced roughness formed under dynamic and gigacycle fatigue loading conditions. Original form of the kinetic equation was proposed, which links the rate of the fatigue crack growth and the stress intensity factor using the scale invariant parameters of fracture surface roughness. The scale invariance characterizes the correlated behavior of multiscale damage provides the link of crack growth kinetics and the power exponent of the modified Paris law.
Authors and Affiliations
Vladimir Oborin, Mikhail Bannikov, Oleg Naimark, Dmitry Bilalov
Keywords
Related Articles
- EP ID EP138396
- DOI 10.3221/IGF-ESIS.34.47
- Views 67
- Downloads 0
Fracture mechanics analyses of the slip-side joggle regions of wing-leading-edge panels
The Space Shuttle wing-leading edge consists of panels that are made of reinforced carbon-carbon. Coating spallation was observed near the slip-side region of the panels that experience extreme heating. To understand t...
Contatto tra i componenti di una protesi di ginocchio: studio numerico e sperimentale
Scopo del presente lavoro è lo studio dell’area di contatto in una protesi di ginocchio utilizzando due differenti approcci. In particolare è stata studiata l’interfaccia fra la componente femorale e l’inserto in p...
Indentation response of a NiTi shape memory alloy: modeling and experiments
The indentation response of a pseudoelastic nickel-titanium based shape memory alloy (SMA) has been analyzed. Indentation tests have been carried out at room temperature using a spherical diamond tip and indentatio...
Effects of large amounts of hydrogen on the fatigue crack growth behavior of torsional prestrained carbon steel
The effects of large amounts of hydrogen on the fatigue crack growth properties of torsional prestrained ferritic–pearlitic low-carbon steel were investigated. Hydrogen-precharged specimens were produced by c...
Plastic zone evolution near a crack tip and its role in environmentally assisted cracking
This paper analyzes the effects of crack tip plastic strains and compressive residual stresses, created by fatigue pre-cracking, on environmentally assisted cracking of pearlitic steel subjected to localized anodic...