Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722126582
Category :
Languages : en
Pages : 34
Book Description
A recently developed, rapidly solidified, powder metallurgy, dispersion strengthened aluminum alloy, AA 8009, was fatigue tested at room temperature in lab air. Constant amplitude/constant delta kappa and single spike overload conditions were examined. High fatigue crack growth rates and low crack closure levels compared to typical ingot metallurgy aluminum alloys were observed. It was proposed that minimal crack roughness, crack path deflection, and limited slip reversibility, resulting from ultra-fine microstructure, were responsible for the relatively poor da/dN-delta kappa performance of AA 8009 as compared to that of typical IM aluminum alloys. Reynolds, A. P. Langley Research Center RTOP 505-63-50-04...
Constant Amplitude and Post-Overload Fatigue Crack Growth Behavior in PM Aluminum Alloy AA 8009
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722126582
Category :
Languages : en
Pages : 34
Book Description
A recently developed, rapidly solidified, powder metallurgy, dispersion strengthened aluminum alloy, AA 8009, was fatigue tested at room temperature in lab air. Constant amplitude/constant delta kappa and single spike overload conditions were examined. High fatigue crack growth rates and low crack closure levels compared to typical ingot metallurgy aluminum alloys were observed. It was proposed that minimal crack roughness, crack path deflection, and limited slip reversibility, resulting from ultra-fine microstructure, were responsible for the relatively poor da/dN-delta kappa performance of AA 8009 as compared to that of typical IM aluminum alloys. Reynolds, A. P. Langley Research Center RTOP 505-63-50-04...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722126582
Category :
Languages : en
Pages : 34
Book Description
A recently developed, rapidly solidified, powder metallurgy, dispersion strengthened aluminum alloy, AA 8009, was fatigue tested at room temperature in lab air. Constant amplitude/constant delta kappa and single spike overload conditions were examined. High fatigue crack growth rates and low crack closure levels compared to typical ingot metallurgy aluminum alloys were observed. It was proposed that minimal crack roughness, crack path deflection, and limited slip reversibility, resulting from ultra-fine microstructure, were responsible for the relatively poor da/dN-delta kappa performance of AA 8009 as compared to that of typical IM aluminum alloys. Reynolds, A. P. Langley Research Center RTOP 505-63-50-04...
Constant Amplitude and Post-overload Fatigue Crack Growth Behavior in PM Aluminum Alloy AA 8009
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 36
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 36
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 296
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 296
Book Description
Advances in Fatigue Crack Closure Measurement and Analysis
Author: R. Craig McClung
Publisher: ASTM International
ISBN: 0803126115
Category : Fracture mechanics
Languages : en
Pages : 487
Book Description
Publisher: ASTM International
ISBN: 0803126115
Category : Fracture mechanics
Languages : en
Pages : 487
Book Description
Applied Mechanics Reviews
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 348
Book Description
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 348
Book Description
Analytical and Experimental Study of Near-Threshold Interactions Between Crack Closure Mechanisms
Author: John A. Newman
Publisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 34
Book Description
Publisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 34
Book Description
Fatigue Crack Growth Behavior of 7XXX Aluminum Alloys Under Simple Variable Amplitude Loading
Author: PE. Bretz
Publisher:
ISBN:
Category : Aluminum alloy
Languages : en
Pages : 24
Book Description
This investigation examines the influence of temper and purity on the fatigue crack growth (FCG) behavior of four 7XXX aluminum alloys (7075-T6, 7075-T7, 7050-T6, 7050-T7) tested using a periodic single overload spectrum at low stresses. The loading sequence consists of a periodic single overload spike occurring once every 8000 constant amplitude cycles; the overload spike is 1.8 times the constant amplitude load peak. All tests have been performed in high humidity (>90% relative humidity) air at a frequency of 20 Hz and a constant amplitude load ratio of R = 0.33. The observed microstructural effects on transient (that is, spectrum) FCG behavior are contrasted with those for steady-state (constant load amplitude) fatigue performance.
Publisher:
ISBN:
Category : Aluminum alloy
Languages : en
Pages : 24
Book Description
This investigation examines the influence of temper and purity on the fatigue crack growth (FCG) behavior of four 7XXX aluminum alloys (7075-T6, 7075-T7, 7050-T6, 7050-T7) tested using a periodic single overload spectrum at low stresses. The loading sequence consists of a periodic single overload spike occurring once every 8000 constant amplitude cycles; the overload spike is 1.8 times the constant amplitude load peak. All tests have been performed in high humidity (>90% relative humidity) air at a frequency of 20 Hz and a constant amplitude load ratio of R = 0.33. The observed microstructural effects on transient (that is, spectrum) FCG behavior are contrasted with those for steady-state (constant load amplitude) fatigue performance.
Government Reports Announcements & Index
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 516
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 516
Book Description
Government reports annual index
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 1846
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 1846
Book Description
Environmental Influence on the Effect of a Single Overload on the Fatigue Crack Growth Behavior on a High-Strength Aluminum Alloy
Author: J. de Fouquet
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 17
Book Description
The delaying effect of a single overload on the 2024 T351 aluminum alloy covering a wide ?K range has been studied in ambient air, secondary vacuum, and high purity nitrogen (N2). It is shown that for a given environment and an overload ratio, the delay behavior can be rationalized in terms of the peak stress intensity factor corresponding to the overload for the studied test conditions. At low ?K values, the overload effect is confined to a grain. The results obtained show that while the size of the overload affected zone is not affected by the environment, the number of delay cycles at an R ratio of 0.5 in vacuum can be ten times as high as that obtained in the two other environments. At an R ratio of 0.1, at low ?K levels, the delaying effects can be similar in vacuum and in air. The observed effects are explained on the basis of mechanisms governing constant-amplitude crack growth behavior of the studied alloy.
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 17
Book Description
The delaying effect of a single overload on the 2024 T351 aluminum alloy covering a wide ?K range has been studied in ambient air, secondary vacuum, and high purity nitrogen (N2). It is shown that for a given environment and an overload ratio, the delay behavior can be rationalized in terms of the peak stress intensity factor corresponding to the overload for the studied test conditions. At low ?K values, the overload effect is confined to a grain. The results obtained show that while the size of the overload affected zone is not affected by the environment, the number of delay cycles at an R ratio of 0.5 in vacuum can be ten times as high as that obtained in the two other environments. At an R ratio of 0.1, at low ?K levels, the delaying effects can be similar in vacuum and in air. The observed effects are explained on the basis of mechanisms governing constant-amplitude crack growth behavior of the studied alloy.