Author : Gregory William Levan
Publisher :
Page : 178 pages
File Size : 34,69 MB
Release : 1984
Category : Aluminum alloys
ISBN :
Author : Wade H. Shafer
Publisher : Springer
Page : 424 pages
File Size : 27,50 MB
Release : 1986
Category : Science
ISBN : 9780306423857
Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 29 (thesis year 1984) a total of 12,637 theses titles from 23 Canadian and 202 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 29 reports theses submitted in 1984, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Author : Richard W. Hertzberg
Publisher : John Wiley & Sons
Page : 800 pages
File Size : 26,86 MB
Release : 2020-07-08
Category : Technology & Engineering
ISBN : 1119670578
Deformation and Fracture Mechanics of Engineering Materials, Sixth Edition, provides a detailed examination of the mechanical behavior of metals, ceramics, polymers, and their composites. Offering an integrated macroscopic/microscopic approach to the subject, this comprehensive textbook features in-depth explanations, plentiful figures and illustrations, and a full array of student and instructor resources. Divided into two sections, the text first introduces the principles of elastic and plastic deformation, including the plastic deformation response of solids and concepts of stress, strain, and stiffness. The following section demonstrates the application of fracture mechanics and materials science principles in solids, including determining material stiffness, strength, toughness, and time-dependent mechanical response. Now offered as an interactive eBook, this fully-revised edition features a wealth of digital assets. More than three hours of high-quality video footage helps students understand the practical applications of key topics, supported by hundreds of PowerPoint slides highlighting important information while strengthening student comprehension. Numerous real-world examples and case studies of actual service failures illustrate the importance of applying fracture mechanics principles in failure analysis. Ideal for college-level courses in metallurgy and materials, mechanical engineering, and civil engineering, this popular is equally valuable for engineers looking to increase their knowledge of the mechanical properties of solids.
Author : EP. Phillips
Publisher :
Page : 11 pages
File Size : 48,80 MB
Release : 1988
Category : Aluminum alloys
ISBN :
Crack opening loads were determined in load-shedding fatigue crack growth threshold tests on 2024-T3 aluminum alloy at stress ratios R of -2, -1, 0, 0.33, 0.5, and 0.7. The effects of load-shedding procedure and rate were investigated. Values of threshold ?K were found to vary significantly with R, whereas values of threshold effective ?K did not. That is, the variation of threshold ?K with R was almost completely explained by accounting for the measured variation in crack opening load behavior with R. The load-shedding guidelines of ASTM Test Method for Measurement of Fatigue Crack Growth (E 647) produced a threshold ?K value for R = 0.7 that was in agreement with the value determined using a procedure that should minimize closure effects (constant-Kmax, increasing-Kmin test). At both R = 0 and R = 0.7, high load-shedding rates produced high values of threshold ?K caused by large closure effects.
Author : HC. Sanders
Publisher :
Page : 12 pages
File Size : 22,94 MB
Release : 2000
Category : Fatigue
ISBN :
The near-threshold fatigue crack growth behavior of the 7075-T651 aluminum alloy was studied in laboratory air, vacuum, and an aqueous 3.5% NaCl solution. Results indicate that a rising stress ratio (R) enhanced the near-threshold fatigue crack growth by increasing the crack growth rate (da/dN) and decreasing the threshold stress intensity range (?Kth) in both laboratory air and aqueous 3.5% NaCl solution. However, the reverse was observed in vacuum. It was also noticed that the near-threshold fatigue crack growth resistance was greatest in vacuum, intermediate in aqueous 3.5% NaCl solution, and lowest in laboratory air. Conversely, the crack growth rate at given values of AK were shown to be greatest in laboratory air, less in 3.5% NaCl solution, and lowest in vacuum. In both laboratory air and aqueous 3.5% NaCl solution, ?Kth, initially decreased with increasing R until a critical stress ratio of Rc = 0.5 was reached, which it then leveled off or decreased slightly. The ?Kth values for these two environments appear to converge at a higher R. On the other hand, in vacuum, the ?Kth, increased linearly with increasing R. In addition, at lower R, a greater resistance to near-threshold fatigue crack growth was detected in aqueous 3.5% NaCl solution than in laboratory air. This is presumably attributed to crack closure that has been induced by accumulation of corrosion product in the crack-tip.
Author :
Publisher :
Page : 11 pages
File Size : 40,71 MB
Release : 1996
Category :
ISBN :
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.
Author :
Publisher :
Page : 11 pages
File Size : 46,8 MB
Release : 2002
Category :
ISBN :
Author : Anthony George Keslinke
Publisher :
Page : 170 pages
File Size : 27,83 MB
Release : 1990
Category :
ISBN :
Author : T. Nicholas
Publisher :
Page : 16 pages
File Size : 14,74 MB
Release : 1994
Category : Composite materials
ISBN :
In the present study, the fatigue crack growth behavior of a near-?, ?-processed titanium alloy, Ti-1100, was investigated with the objective of assessing the influence of crack closure and stress ratio on fatigue threshold. Measurement of the crack-opening load in single-edge tension [SE(T)] specimens was made by near-tip strain gage and DCPD methods. Fatigue threshold stress intensity ranges, ?Kth, determined under constant stress ratio and constant maximum stress intensity, variable stress ratio conditions indicate almost identical values for R above 0.5. It is postulated that while crack closure in the wake of the crack tip is responsible for the no-growth condition in the former case, lack of sufficient damage accumulation at the crack tip as a consequence of the formation of an insignificant reversed plastic zone and large planar slip band formations surrounding the crack tip appears to be responsible for no growth in the latter case. The use of an effective stress intensity based on closure data consolidates most of the threshold data, indicating the independence of the fatigue crack growth data to mean stress or R.
Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 26 pages
File Size : 17,6 MB
Release : 2018-06-19
Category :
ISBN : 9781721502271
Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent. Piascik, Robert S. and Newman, John A. Langley Research Center NASA/TM-2002-211676, L-18180, NAS 1.15:211676, ARL-TR-2728
