Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781726673556
Category : Science
Languages : en
Pages : 38
Book Description
Fatigue and crack growth tests have been conducted on 4340 steel and 2024-T3 aluminum alloy, respectively, to assess the effects of shot peening on fatigue life and the effects of shot and laser peening on crack growth. Two current programs involving fixed and rotary-wing aircraft will not be using shot peened structures. Since the shot peening compressive residual stress depth is usually less than the 0.05-inch initial damage tolerance crack size, it is believed by some that shot peening should have no beneficial effects toward retarding crack growth. In this study cracks were initiated from an electronic-discharged machining flaw which was cycled to produce a fatigue crack of approximately 0.05-inches in length and then the specimens were peened. Test results showed that after peening the crack growth rates were noticeably slower when the cracks were fairly short for both the shot and laser peened specimens resulting in a crack growth life that was a factor of 2 to 4 times greater than the results of the average unpeened test. Once the cracks reached a length of approximately 0.1-inches the growth rates were about the same for the peened and unpeened specimens. Fatigue tests on 4340 steel showed that the endurance limit of a test specimen with a 0.002-inch-deep machining-like scratch was reduced by approximately 40 percent. However, if the "scratched" specimen was shot peened after inserting the scratch, the fatigue life returned to almost 100 percent of the unflawed specimens original fatigue life. Everett, R. A., Jr. and Matthews, W. T. and Prabhakaran, R. and Newman, J. C., Jr. and Dubberly, M. J. Langley Research Center NASA/TM-2001-210843, NAS 1.15:210843, ARL-TR-2363, L-18065
The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781726673556
Category : Science
Languages : en
Pages : 38
Book Description
Fatigue and crack growth tests have been conducted on 4340 steel and 2024-T3 aluminum alloy, respectively, to assess the effects of shot peening on fatigue life and the effects of shot and laser peening on crack growth. Two current programs involving fixed and rotary-wing aircraft will not be using shot peened structures. Since the shot peening compressive residual stress depth is usually less than the 0.05-inch initial damage tolerance crack size, it is believed by some that shot peening should have no beneficial effects toward retarding crack growth. In this study cracks were initiated from an electronic-discharged machining flaw which was cycled to produce a fatigue crack of approximately 0.05-inches in length and then the specimens were peened. Test results showed that after peening the crack growth rates were noticeably slower when the cracks were fairly short for both the shot and laser peened specimens resulting in a crack growth life that was a factor of 2 to 4 times greater than the results of the average unpeened test. Once the cracks reached a length of approximately 0.1-inches the growth rates were about the same for the peened and unpeened specimens. Fatigue tests on 4340 steel showed that the endurance limit of a test specimen with a 0.002-inch-deep machining-like scratch was reduced by approximately 40 percent. However, if the "scratched" specimen was shot peened after inserting the scratch, the fatigue life returned to almost 100 percent of the unflawed specimens original fatigue life. Everett, R. A., Jr. and Matthews, W. T. and Prabhakaran, R. and Newman, J. C., Jr. and Dubberly, M. J. Langley Research Center NASA/TM-2001-210843, NAS 1.15:210843, ARL-TR-2363, L-18065
Publisher: Independently Published
ISBN: 9781726673556
Category : Science
Languages : en
Pages : 38
Book Description
Fatigue and crack growth tests have been conducted on 4340 steel and 2024-T3 aluminum alloy, respectively, to assess the effects of shot peening on fatigue life and the effects of shot and laser peening on crack growth. Two current programs involving fixed and rotary-wing aircraft will not be using shot peened structures. Since the shot peening compressive residual stress depth is usually less than the 0.05-inch initial damage tolerance crack size, it is believed by some that shot peening should have no beneficial effects toward retarding crack growth. In this study cracks were initiated from an electronic-discharged machining flaw which was cycled to produce a fatigue crack of approximately 0.05-inches in length and then the specimens were peened. Test results showed that after peening the crack growth rates were noticeably slower when the cracks were fairly short for both the shot and laser peened specimens resulting in a crack growth life that was a factor of 2 to 4 times greater than the results of the average unpeened test. Once the cracks reached a length of approximately 0.1-inches the growth rates were about the same for the peened and unpeened specimens. Fatigue tests on 4340 steel showed that the endurance limit of a test specimen with a 0.002-inch-deep machining-like scratch was reduced by approximately 40 percent. However, if the "scratched" specimen was shot peened after inserting the scratch, the fatigue life returned to almost 100 percent of the unflawed specimens original fatigue life. Everett, R. A., Jr. and Matthews, W. T. and Prabhakaran, R. and Newman, J. C., Jr. and Dubberly, M. J. Langley Research Center NASA/TM-2001-210843, NAS 1.15:210843, ARL-TR-2363, L-18065
The Effect of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel ... Nasa
Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 26
Book Description
The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel
Author:
Publisher:
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 18
Book Description
Publisher:
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 18
Book Description
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 882
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 882
Book Description
Proceedings of Crack Paths (CP 2009), Vicenza, Italy 2009
Author:
Publisher: Gruppo Italiano Frattura
ISBN: 8895940288
Category :
Languages : en
Pages : 1129
Book Description
Publisher: Gruppo Italiano Frattura
ISBN: 8895940288
Category :
Languages : en
Pages : 1129
Book Description
NASA Langley Scientific and Technical Information Output 2000
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 162
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 162
Book Description
NASA Langley Scientific and Technical Information Output-2001
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 166
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 166
Book Description
The Effects of Scratches and Shot Peening on the Fatigue Crack Growth of AL Alloy 2024-T3
Author: Min Shao
Publisher:
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 274
Book Description
Publisher:
ISBN:
Category : Aluminum alloys
Languages : en
Pages : 274
Book Description
Fatigue Life Extension and the Effects of Laser Peening on 7050-T7451 Aluminum, 7085-T7651 Aluminum, and Ti-6Al-4V Titanium Alloys
Author: Harold Luong
Publisher:
ISBN:
Category :
Languages : en
Pages : 196
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 196
Book Description