Download or read book Experimentally Derived Beta Corrections to Predict Fatigue Crack Growth at Cold Expanded Holes in 7075 T651 Aluminum Alloy written by Robert Thomas Pilarczyk and published by . This book was released on 2008 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimentally Derived Beta Corrections to Accurately Model the Fatigue Crack Growth Behavior at Cold Expanded Holes in 2024 T351 Aluminum Alloys written by Scott Spencer Carlson and published by . This book was released on 2008 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ICAF 2019 Structural Integrity in the Age of Additive Manufacturing written by Antoni Niepokolczycki and published by Springer. This book was released on 2019-07-03 with total page 1164 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers papers presented at the 36th conference and 30th Symposium of the International Committee on Aeronautical Fatigue and Structural integrity. Focusing on the main theme of “Structural Integrity in the Age of Additive Manufacturing”, the chapters cover different aspects concerning research, developments and challenges in this field, offering a timely reference guide to designers, regulators, manufacturer, and both researchers and professionals of the broad aerospace community.
Download or read book 7075 T6 and 2024 T351 Aluminum Alloy Fatigue Crack Growth Rate Data written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental test procedures for the development of fatigue crack growth rate data has been standardized by the American Society for Testing and Materials. Over the past 30 years several gradual changes have been made to the standard without rigorous assessment of the affect these changes have on the precision or variability of the data generated. Therefore, the ASTM committee on fatigue crack growth has initiated an international round robin test program to assess the precision and variability of test results generated using the standard E647-00. Crack growth rate data presented in this report, in support of the ASTM roundrobin, shows excellent precision and repeatability. Forth, Scott C. and Wright, Christopher W. and Johnston, William M., Jr. Langley Research Center NASA/TM-2005-213907, L-19163
Download or read book Environmentally Influenced Near Threshold Fatigue Crack Growth in 7075 T651 Aluminum Alloy written by and published by . This book was released on 1996 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The near-threshold fatigue crack growth behavior of a 7075-T651 aluminum alloy was studied in laboratory air, vacuum, and an aqueous 3.5% NaCl solution. Results obtained indicate that raising the stress ratio R enhanced the near-threshold fatigue crack growth with a greater crack growth rate da/dN and smaller threshold stress intensity range deltaK(th) in laboratory air and an aqueous 3.5% NaCl solution. However, the reverse was observed in vacuum. The near-threshold fatigue crack growth was most sluggish with the smallest da/dN and greatest deltaK(th) values in vacuum, intermediate with an intermediate da/dN and deltaK(th) in the aqueous 3.5% NaCl solution, and fastest with the greatest da/dN and smallest deltaK(th) values in laboratory air. In laboratory air and aqueous 3.5% NaCl solution deltaK(th) initially decreased with increasing R until a value of 0.5 was reached, and then leveled off or decreased slightly. The detlaK(th) values for these two environments appear to converge at a higher R. On the other hand, in vacuum, the deltaK(th) increased linearly with increasing R. In addition, at lower R, a greater resistance to near-threshold fatigue crack growth was detected in the aqueous 3.5% NaCl solution than in laboratory air. This is attributable to crack closure, induced by corrosion product at the crack tip.
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 7075 T6 and 2024 T351 Aluminum Alloy Fatigue Crack Growth Rate Data written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-07 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NASA Technical Reports Server (NTRS) houses half a million publications that are a valuable means of information to researchers, teachers, students, and the general public. These documents are all aerospace related with much scientific and technical information created or funded by NASA. Some types of documents include conference papers, research reports, meeting papers, journal articles and more. This is one of those documents.
Download or read book Fatigue Crack Growth Arrest and Reinitiation Along a Row of Holes written by T. R. Brussat and published by . This book was released on 1974 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth along a row of fastener-sized holes in 7075-T6 Aluminum sheet is investigated experimentally and analytically. The cracking sequence is punctuated by substantial periods of crack reinitiation with each arrestment at a hole. Two methods for estimating the duration of these crack reinitiation periods are developed and compared with the test data. The use of crack nucleation data and theory for such estimation appears to more closely predict test results than the use of fracture mechanics analysis with an assumed .005 inch preexisting microcrack. (This conclusion is relevant to the 'continuing damage analysis' requirements in the Air Force's 'Damage Tolerance Design Requirements'.) Some new formulas for stress concentration factors and stress intensity factors are presented. Further, the discussion of the significance of the elastic stress field near a long notch is offered which may have useful implications for fatigue analysis.
Download or read book Prediction of Fatigue crack propagation Behavior in Panels with Simulated Rivet Forces written by United States. National Aeronautics and Space Administration and published by . This book was released on 1968 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Stress Ratio on Fatigue Crack Growth Rate at Notched Hole in 7075 T6 Aluminum Alloy Under Biaxial Fatigue written by Reja Alshahrani (Capt., RSAF.) and published by . This book was released on 2016 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Life and Crack Growth Prediction Methodology written by J. C. Newman (Jr) and published by . This book was released on 1993 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prediction of Fatigue Crack growth Patterns and Lives in Three dimensional Cracked Bodies written by and published by . This book was released on 1984 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Fatigue Crack Propagation in AA 7075 T651 written by Robert Blandford and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To better design structures and machines, understanding of flaws and failures is essential. The body of this work has addressed numerous facets of fatigue crack propagation. The affect of crack closure, testing errors, and data scatter are a few important components of crack growth developed and investigated. It was found that the widely accepted compliance-offset technique for closure measurement may be sensitive to increases in load ratio. Opening load uncertainty was calculated to be on the order of 5%. The application of practical regression techniques and the use of DKeff were used to characterize closure-free crack growth data to develop a single intrinsic da/dN curve. The best form of regression was found to be a multi-linear fit. A strip-yield model requiring the intrinsic curve was used to successfully predict crack growth at other load ratios. Uncertainties with a strong dependence on crack mouth displacement were found for da/dN, DK, and a. To better design structures and machines, understanding of flaws and failures is essential. The body of this work has addressed numerous facets of fatigue crack propagation. The affect of crack closure, testing errors, and data scatter are a few important components of crack growth developed and investigated. It was found that the widely accepted compliance-offset technique for closure measurement may be sensitive to increases in load ratio. Opening load uncertainty was calculated to be on the order of 5%. The application of practical regression techniques and the use of DKeff were used to characterize closure-free crack growth data to develop a single intrinsic da/dN curve. The best form of regression was found to be a multi-linear fit. A strip-yield model requiring the intrinsic curve was used to successfully predict crack growth at other load ratios. Uncertainties with a strong dependence on crack mouth displacement were found for da/dN, deltaK, and a.
Download or read book Modelling of Fatigue Crack Growth in 7075 T651 Aluminium Alloy Plate written by R. J. H. Wanhill and published by . This book was released on 1985 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predicting Fatigue Crack Growth in the Residual Stress Field of a Cold Worked Hole written by Jude H. Restis and published by . This book was released on 2007 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold working of holes generates compressive residual stresses resulting in a significant fatigue life improvement over a non-cold worked hole. Current fatigue life prediction methods for cold worked holes are based on two-dimensional (2-D) linear superposition of stress intensity factor, K, solutions of the non-cold worked hole and the residual stresses. Such predictions have shown various levels of agreement with the overall fatigue life and have generally underpredicted the crack growth over the majority of life. An inverse process was used to generate K solutions for the residual stresses of two experimental data sets using AFGROW and the crack growth data from the experiments. The inverse K solutions were inconsistent with the residual stress distribution indicating that it contained mechanisms or features not inherent to the 2-D weight function method. The predicted fatigue life was found to be very sensitive to a ± 1 % variance in the inversely generated K solution. This sensitivity of the K method is a very important issue that must be addressed in the future. A 2-D FEA model indicated that the crack remained completely closed over a range of crack lengths despite experimental crack growth indicating that the model was not an accurate physical representation of the real crack. The results of this study combined with the significantly faster crack growth observed on the side of the hole corresponding to the entry side of the mandrel and the through thickness residual hoop stress variation show that the current methodology based on a 2-D assumptions is inadequate in predicting the fatigue crack growth from cold worked holes for the range of specimen thicknesses in this study. It is suggested that further research focus on incorporating the through thickness stress variance in a solution that predicts crack growth both in the radial and through thickness directions to capture the peculiar crack growth associated with cold working.
Download or read book Predicting Fatigue Crack Growth in the Residual Stress Field of a Cold Worked Hole written by MT. Kokaly and published by . This book was released on 2005 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold working of holes generates compressive residual stresses resulting in a significant fatigue life improvement over a non-cold worked hole. Current fatigue life prediction methods for cold worked holes are based on two-dimensional (2-D) linear superposition of stress intensity factor, K, solutions of the non-cold worked hole and the residual stresses. Such predictions have shown various levels of agreement with the overall fatigue life and have generally underpredicted the crack growth over the majority of life. An inverse process was used to generate K solutions for the residual stresses of two experimental data sets using AFGROW and the crack growth data from the experiments. The inverse K solutions were inconsistent with the residual stress distribution indicating that it contained mechanisms or features not inherent to the 2-D weight function method. The predicted fatigue life was found to be very sensitive to a ± 1% variance in the inversely generated K solution. This sensitivity of the K method is a very important issue that must be addressed in the future. A 2-D FEA model indicated that the crack remained completely closed over a range of crack lengths despite experimental crack growth indicating that the model was not an accurate physical representation of the real crack. The results of this study combined with the significantly faster crack growth observed on the side of the hole corresponding to the entry side of the mandrel and the through thickness residual hoop stress variation show that the current methodology based on a 2-D assumptions is inadequate in predicting the fatigue crack growth from cold worked holes for the range of specimen thicknesses in this study. It is suggested that further research focus on incorporating the through thickness stress variance in a solution that predicts crack growth both in the radial and through thickness directions to capture the peculiar crack growth associated with cold working.
Download or read book Fatigue Crack Growth Rate Data for Aluminum Alloy 6061 T651 Plate written by and published by . This book was released on 1984 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constant amplitude fatigue crack growth rate data were obtained for aluminum alloy 6061-T651 plate. Such data were obtained at two stress ratios, R=0.1 and 0.5, at room temperature and 300 deg F. Both the T-L and L-T orientations of a single 1/2-inch (13mm) thick plate were examined. Final crack growth rate data are presented in both graphical and tabular formats, using the analyses and presentation schemes developed by the University of Dayton Research Institute for he Revised Damage Tolerant Design Handbook. (Author).
