Crack-Closure Behavior of 7050 Aluminum Alloy near Threshold Conditions for Wide Range in Load Ratios and Constant

2011 ◽  
pp. 297-297-23
Author(s):  
J. C. Newman ◽  
Y. Yamada ◽  
J. A. Newman
Keyword(s):  
Aluminum Alloy ◽  
Crack Closure ◽  
7050 Aluminum Alloy ◽  
Wide Range ◽  
Threshold Conditions ◽  
Near Threshold

Crack-Closure Behavior of 7050 Aluminum Alloy near Threshold Conditions for Wide Range in Load Ratios and Constant Kmax Tests

2010 ◽  
Vol 7 (4) ◽  
pp. 102490 ◽  
Author(s):  
J. C. Newman ◽  
Y. Yamada ◽  
J. A. Newman ◽  
S. Kalluri ◽  
R. M. McGaw ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Crack Closure ◽  
7050 Aluminum Alloy ◽  
Wide Range ◽  
Threshold Conditions ◽  
Near Threshold

The Effect of Sheet Thickness on Near-Threshold Fatigue Crack Propagation and Oxide and Roughness-Induced Crack Closure

1987 ◽  
Vol 109 (1) ◽  
pp. 86-91 ◽  
Author(s):  
K. Tokaji ◽  
Z. Ando ◽  
K. Nagae
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Crack Closure ◽  
Growth Rates ◽  
Sheet Thickness ◽  
Specimen Thickness ◽  
Low Carbon ◽  
Wide Range ◽  
Near Threshold

Characteristics of fatigue crack propagation have been investigated in a low carbon steel and a high tensile strength steel to evaluate the effect of sheet thickness. Crack propagation data are generated over a wide range of growth rates, from 10−8 to 10−3 mm/cycle, for load ratios of 0.05 and 0.70 at room temperature in laboratory air. Particular emphasis is placed on behavior at near-threshold growth rates. Near-threshold fatigue crack propagation behavior is found to show a marked sensitivity to sheet thickness, and near-threshold growth rates decrease and threshold values increase with increasing sheet thickness. Oxide and roughness-induced crack closure models are proposed as a mechanism for the effect of sheet thickness on near-threshold fatigue crack propagation. It is also shown that the requirement for specimen thickness recommended by ASTM, W/20≤B≤W/4, is not always valid for near-threshold fatigue crack propagation.

Crack Closure Behavior under High-Load Ratio for AISI 4340 Steel

2011 ◽  
Vol 462-463 ◽  
pp. 54-58
Author(s):  
M. Abdul Razzaq ◽  
Ahmad Kamal Ariffin ◽  
Shahrum Abdullah ◽  
Z. Sajuri
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Closure ◽  
Fatigue Crack Growth Rate ◽  
Threshold Conditions ◽  
Near Threshold ◽  
Aisi 4340

In this paper, fatigue crack growth rate (FCGR) analyses were conducted on compact specimens of an AISI 4340 alloy to study the behavior over a range in load ratios (0.1 ≤ R ≤ 0.95) and constant maximum stress intensity factor (Kmax) condition. Previous study had indicated that high R > 0.7 and constant Kmax test conditions near threshold conditions were suspected to be free of crack-closure and that any differences were caused by Kmax effects, from threshold to near fracture conditions. Cracks in high-cycle fatigue (HCF) components spend a large portion of their fatigue life near threshold conditions. In order to characterize the evolution of damage and crack propagation during these conditions, fatigue crack growth rate (FCGR) data at threshold and near-threshold conditions are essential in predicting service life and in determining the proper inspection intervals. Fatigue crack growth model, namely the Forman model were examined, this model implicit the effect of R ratio and ease of curve fitting to measured data. The Forman model may be suggested for use in critical applications in studying fatigue crack growth for different load ratios.

Micromechanical behavior study of forged 7050 aluminum alloy by microindentation

2012 ◽  
Vol 37 ◽  
pp. 491-499 ◽  
Author(s):  
Jiang Li ◽  
Fuguo Li ◽  
Fengmei Xue ◽  
Jun Cai ◽  
Bo Chen
Keyword(s):  
Aluminum Alloy ◽  
Behavior Study ◽  
7050 Aluminum Alloy
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