Download or read book The Effects of Shot Peening on Fatigue Crack Propagation in 7075 T7351 Aluminum Alloy SENB Specimens written by Thomas Pettit Munson and published by . This book was released on 2004 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Shot Peening on Fatigue Crack Growth in 7075 T7351 written by T. Honda and published by . This book was released on 2005 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of shot peening on fatigue crack growth in 7075-T735 single-edged notch bend (SENB) and three point bend (TPB) specimens are discussed. Fifty-one total fatigue tests were conducted with SENB and TPB specimens, which were machined from an 8.1 mm thick 7075-T7351 aluminum stock plate. All specimens were tested in the as-received or shot peened conditions, with crack perpendicular to the rolling direction, i.e., in the L-T direction. Fatigue tests of SENB specimens were conducted at a constant maximum load, stress ratios of R = 0.1 or 0.8, and to a pre-determined fatigue cycle or to failure. Crack growth rate was determined from the tunneling crack profile or by fractography. Peened surface roughness, subsurface microstructure, and micro-hardness profiles were also examined to evaluate their effect on crack growth rate. The TPB specimens were fatigued to failure at stress ratios of R = 0.1 or 0.8 and a S-N diagram constructed. Both the SENB and the TPB test results showed that severe shot peening (0.016A) slightly increased the fatigue life at low stress ratio of R = 0.1 but was found to be negligible at a high load ratio of R = 0.8. The stress concentration factor due to dimples generated by severe shot peening was estimated to be 1.14 and had negligible effect on the fatigue life. Grain distortion was observed to a depth range of 130-410 μm indicating the depth of the residual compressive stress layer developed for peening intensities of 0.004-0.016A, respectively.

Download or read book Residual Stress Effects on Fatigue and Fracture Testing and Incorporation of Results Into Design written by Michael R. Mitchell and published by ASTM International. This book was released on 2007 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Eleven peer-reviewed papers, written by experts in their field, provide an understanding of residual stresses, fatigue crack growth, fatigue lifetime predictions, and their effect on structural integrity. Residual stresses can be present due to processing and manufacturing of materials and structures, so it is imperative to understand how and why they can influence the test data that we used in structural design methodologies. Residual stresses may also be intentionally engineered into structures in attempts to improve fatigue life, and it is equally important that designers understand how to account for these potential effects on fatigue life."--Publisher's website.

Download or read book Effect of Shot Peening on Fatigue Crack Growth in 7075 T7351 written by M. Ramulu and published by . This book was released on 2007 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of shot peening on fatigue crack growth in 7075-T735 single-edged notch bend (SENB) and three point bend (TPB) specimens are discussed. Fifty-one total fatigue tests were conducted with SENB and TPB specimens, which were machined from an 8.1 mm thick 7075-T7351 aluminum stock plate. All specimens were tested in the as-received or shot peened conditions, with crack perpendicular to the rolling direction, i.e., in the L-T direction. Fatigue tests of SENB specimens were conducted at a constant maximum load, stress ratios of R = 0.1 or 0.8, and to a pre-determined fatigue cycle or to failure. Crack growth rate was determined from the tunneling crack profile or by fractography. Peened surface roughness, subsurface microstructure, and micro-hardness profiles were also examined to evaluate their effect on crack growth rate. The TPB specimens were fatigued to failure at stress ratios of R = 0.1 or 0.8 and a S-N diagram constructed. Both the SENB and the TPB test results showed that severe shot peening (0.016A) slightly increased the fatigue life at low stress ratio of R = 0.1 but was found to be negligible at a high load ratio of R = 0.8. The stress concentration factor due to dimples generated by severe shot peening was estimated to be 1.14 and had negligible effect on the fatigue life. Grain distortion was observed to a depth range of 130-410 ?m indicating the depth of the residual compressive stress layer developed for peening intensities of 0.004-0.016A, respectively.

Download or read book The Effect of Shot peening on Fatigue Crack Growth Behavior of the 7475 T7351 Aluminum Alloy written by Julien Le Vely and published by . This book was released on 2001 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel written by and published by . This book was released on 2001 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-03 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Advances in Fracture and Strength written by Young Jin Kim and published by Trans Tech Publications Ltd. This book was released on 2005-11-15 with total page 3000 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). This volume comprises selected papers from the Asian Pacific Conference for Fracture and Strength (APCFS’04), held on Jeju Island, Korea during the 6th to 8th October, 2004. During this conference, participants from the Asian-Pacific region gathered in order to exchange the latest experimental, theoretical and computational research on the fracture, strength, integrity and reliability of materials and structures.

Download or read book The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel written by and published by . This book was released on 2001 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of the Effects of Different Peening Techniques on the Fatigue Crack Propagation in Aluminum Alloy 7075 T6 written by Temitope Rotimi Adekola and published by . This book was released on 2006 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture and Fatigue Crack Propagation Characteristics of 7075 t7351 Aluminum Alloy Sheet and Plate written by Charles E. Feddersen and published by . This book was released on 1970 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The program was directed to provide information relative to damage tolerance of panels of 7075-T7351 sheet and plate. This implied the generation and analysis of information on flat panels containing centrally located flaws and testing, either under monotonically increasing load or under cyclic loads. The information obtained provided insight into the two major aspects of damage tolerance - residual strength and fatigue-crack propagation - from tests on panels ranging in thickness from 1/16 inch to 1 inch and in width from 8 inches to 36 inches. The program has shown that there are at least two bench marks in crack growth behavior from the monotonically increasing load test: (1) onset of slow growth at which a flaw initially present begins to grow slowly with increasing load, and (2) critical instability at which unstable and rapid crack growth occurs that results in failure. From the data obtained a generalized residual strength analysis was developed which identifies a fracture toughness property for thin and transition thickness materials as well as presents design data and fracture or residual strength predictions for structural applications. The program has also resulted in the identification of an empirical expression that appears to be quite useful in predicting fatigue-crack propagation and the remaining lifetime of a panel containing a fatigue crack. (Author).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shot Peening written by Lothar Wagner and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shot peening has been proved to be a powerful instrument in enhancing the resistance of materials to various kinds of stress-induced damage, particularly against damage due to cyclic loading (fatigue) in air or in aggressive environments. As shot peening can be used for a wide variety of structural components irrespective of shape and dimensions, the number of shot peening applications in many industrial branches is increasing. The use of peen forming as a technique to form large metal parts into complicated shapes is also increasing, particularly in the aerospace industry. The Conference covers all aspects of the Science, Technology and Application of Shot Peening, and was intended to attract users, manufacturers as well as scientists working in the field of "Materials Treatment by Shot Peening". Emphasis was put on the current state of knowledge and research. This book offers scientists and engineers an unique opportunity to update their knowledge on shot peening.

Download or read book The Effects of Grain Distribution on Initiation and Propagation of Fatigue Cracks in 7075 T6 Aluminum Alloy Sheet written by James M. Schwindle and published by . This book was released on 1971 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was made to determine a mechanism for initiation and propagation of fatigue cracks in 7075-T6 Alclad aluminum alloy sheet specimens subjected to cyclic tensile stresses. Fatigue fracture modes observed with the scanning electron microscope and a light microscope were compared to photomicrographs of polished and etched fracture surfaces of both laboratory and service failures. It was found that fatigue cracks always initiated between grain boundaries of grain fibers which extended to the surface of specimens. Laboratory failures did not exhibit crack morphology similar to that of service failures. It is believed that significant improvements in fatigue resistance could be obtained in specimens having reduced grain size and regular distribution of grain fibers in a direction parallel to the tensile stress direction. (Modified author abstract).

Download or read book Effects of Bonding Temperatures on Fatigue Crack Growth written by Rodney L. Wilkinson and published by . This book was released on 1983 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Changes in the crack growth behavior of 7075-T651 aluminum specimens which has been exposed to temperatures between 150 degrees and 355 degrees F (66 deg and 179 deg C) were evaluated. Specimens were fatigue tested at room temperature under flight-by-flight loading conditions. Results from these tests were then compared with data from the baseline (as received) material. Exposure to 250 deg F (121 deg C) or more produced a definite increase in speciment life, apparently due to a decrease in crack growth rates.

Download or read book The Effects of Scratches and Shot Peening on the Fatigue Crack Growth of AL Alloy 2024 T3 written by Min Shao and published by . This book was released on 1995 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shot Peening for Improved Fatigue Properties and Stress corrosion Resistance written by James Edward Campbell and published by . This book was released on 1971 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shot peening procedures developed over the past 40 years have resulted in substantial improvements in fatigue properties and stress corrosion resistance of high-strength alloys. These improvements have been observed in shot-peened specimens and components of high-strength steels, aluminum alloys, titanium alloys, and other engineering alloys. This report contains information on peening procedures that have been used in processing specimens and components to achieve these improvements in performance. Certain precautions are pointed out that should be observed in order to obtain the improved properties that have been attributed to the peening process. Some of the peening programs cited in this report indicate the peening intensities that resulted in the greatest benefit in performance based on test data covering a range of intensities, shot sizes, and other variables. (Author).