An Experiment of Fatigue Crack Growth under Different R-Ratio for 2024-T4 Aluminum Alloy

2011 ◽  
Vol 66-68 ◽  
pp. 1477-1482 ◽  
Author(s):  
Guang Yang ◽  
Zeng Liang Gao ◽  
Feng Xu ◽  
Xiao Gui Wang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Great Influence ◽  
Ambient Air ◽  
Compact Tension ◽  
Growth Region ◽  
Paris Law ◽  
Growth Experiments

The fatigue crack growth tests of compact tension (CT) specimens of 2024-T4 aluminum alloy were conducted under constant amplitude loading with differentR-ratios, 0.05, 0.1, 0.5, 0.75, respectively. The thickness of the specimen is 3.8mm. All the fatigue crack growth experiments were carried out in ambient air without a pre-crack. The early crack growth region reflects the influence of the notch. An optical reading micrometer with a magnification of 40 was used to measure the crack length. The size of the notch together with the loading conditions has a great influence on the early crack growth within the notch influenced region. Beyond the notch influenced zone, the stable fatigue crack growth is reached and can be characterized by the Paris law. The experimental results indicate that fatigue crack growth rate increases with theR-ratio for a given stress intensity factor amplitude.

Grey Relational Grade Analysis between Vickers Hardness and Fatigue Crack Growth Data of 2024-T351 Aluminum Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 2435-2439 ◽  
Author(s):  
Chih Chung Ni
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Vickers Hardness ◽  
Compact Tension ◽  
Growth Data ◽  
Alloy Plate ◽  
Grey Relational Grade ◽  
Grey Relational

Compact tension specimens cut from 2024-T351 aluminum-alloy plate were used for Vickers hardness tests under low-force scale and then for fatigue crack growth tests under sinusoidal loads, and the scattered data sets obtained including Vickers hardness, initiation cycle and specimen life, exponent m and intercept C of Paris-Erdogan law were collected as a factor set with five factor series for analysis of grey relational grade. Nominal value method was adopted for the preprocess referred to as grey relational generation to obtained new factor series, and then Hsia’s method was used to calculate the grey relational grades among new factor series. The analyzed result named global grey relational grade in matrix form with dimension of shows three main findings: (1) Vickers hardness has the largest influence on specimen life, and vice versa. (2) Vickers hardness, specimen life, and m have a large influence on each other. (3) C has the least influence on any other factors, and vice versa.

Study on Fatigue Crack Growth of 6065-T4 Aluminium Alloy at Different Stress Ratio

2013 ◽  
Vol 393 ◽  
pp. 435-440
Author(s):  
Mohd Suhairil Meon ◽  
Hazran Husain ◽  
Muhamad Fauzi Othman ◽  
Juri B. Saedon ◽  
Mohd Izzul Khairi Zailani
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Aluminium Alloy ◽  
Crack Growth ◽  
Room Temperature ◽  
Stress Ratio ◽  
Compact Tension ◽  
Paris Law ◽  
R Ratio ◽  
Before And After

Fatigue crack growth (FCG) rates of compact tension (CT) specimens of Aluminium alloy 6065-T4 were investigated at room temperature and constant amplitude loadings. Standard CT specimens with pre-cracked according to ASTM E647-E11 were subjected to mode I loading with three R-ratio (0.1, 0.3, and 0.5). Paris law has been used to model the stress ratio effect. A stereozoom microscope was used to observe the microstructure changes before and after the tests. The results indicated that the higher the stress ratio value (from 0.1 to 0.5), the faster the FCG rates on CT specimen of AA 6065-T4.

Thickness Effects on the Fatigue Crack Growth Rate of 2024-T4 Aluminum Alloy

2011 ◽  
Vol 66-68 ◽  
pp. 1592-1597
Author(s):  
Feng Xu ◽  
Xiao Gui Wang ◽  
Guang Yang ◽  
Zeng Liang Gao
Keyword(s):  
Growth Rate ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Standard Form ◽  
Stable Crack Growth ◽  
Paris Law

The fatigue crack growth experiments of 2024-T4 aluminum alloy were carried out to study the thickness effects on the fatigue crack growth rate. Round compact specimens with two different thickness, 3.8mm and 12.5mm, were subjected to Mode I loading with fourR-ratios (0.05, 0.1, 0.5 and 0.75) and loading amplitudes. An optical reading microscope with a magnification of 40 was used to measure the crack length. Stable crack growth is characterized by the standard form of the Paris law, material constants of the Paris law corresponding to eachR-ratio were obtained by fitting the experimental data. The fatigue crack growth rate of specimens with a thickness of 12.5mm is apparently higher than that of specimens with a thickness of 3.8mm whenR-ratio is equal to 0.1, 0.5 and 0.75. While the effect of thickness is relatively less significant for the case of. It can be concluded that the fatigue crack growth rate increases with R-ratio or thickness when one of them is identical.

Micromechanisms of multistage fatigue crack growth in a high-strength aluminum alloy

2007 ◽  
Vol 55 (6) ◽  
pp. 1975-1984 ◽  
Author(s):  
Y. Xue ◽  
H. El Kadiri ◽  
M.F. Horstemeyer ◽  
J.B. Jordon ◽  
H. Weiland
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
High Strength ◽  
High Strength Aluminum Alloy

Corrosion-Fatigue Crack Growth in Age-Hardened Al Alloys: Examples of Failures and Explanations for Fractographic Observations

2014 ◽  
Vol 891-892 ◽  
pp. 248-253 ◽  
Author(s):  
Rohan Byrnes ◽  
Noel Goldsmith ◽  
Mark Knop ◽  
Stan Lynch
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Corrosion Fatigue ◽  
Compact Tension ◽  
Al Alloys ◽  
Corrosion Fatigue Crack ◽  
Crack Tips ◽  
Corrosion Fatigue Crack Growth ◽  
Additional Support

The characteristics of corrosion-fatigue in age-hardened Al alloys, e.g. brittle striations on cleavage-like facets, are described, with reference to two examples of component failure. Mechanisms of corrosion fatigue (and explanations for fracture-surface features) are then reviewed. New observations of corrosion-fatigue crack growth for 7050-T7451 alloy compact-tension specimens tested in aqueous environments using a constant (intermediate) ΔK value but different cycle frequencies are then described and discussed. These observations provide additional support for a hydrogen-embrittlement process involving adsorption-induced dislocation-emission from crack tips.

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