Download or read book Fatigue Crack Growth and Crack Closure Behavior of Ti 6Al 4V Alloy Under Variable Amplitude Loadings written by M. Jono and published by . This book was released on 1999 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth tests under constant-amplitude and repeated two-step loadings were carried out on a (? + ?) Ti-6Al-4V alloy which has duplex structure made up of equiaxed primary ?-phase grains with a discontinuous fine ?-phase dispersed in the boundaries. It was found that fatigue crack grew along ?-phase grain boundaries and that the fracture surface was very rough in the low stress intensity region under constant-amplitude loading. On the other hand, in the high region, transgranular crack growth was observed and the fracture surface was relatively smooth. The crack opening point, Kop, was affected by the amplitude of low-level load, ?KL, under repeated two-step loadings where the high-level load amplitude was kept constant. Kop was found to be higher than that predicted by Kop -- Kmax relationship under constant-amplitude loading and the fracture surface was rougher in comparison with that under constant-amplitude loading which has the identical stress intensity range. It was concluded that the crack opening point was controlled by both plasticity-induced crack closure in terms ofKmax and roughness-induced crack closure resulted from rougher surface in ?KL.

Download or read book Fatigue Crack Growth Under Spectrum Loads written by Ralph Ivan Stephens and published by ASTM International. This book was released on 1976 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Fatigue Crack Closure Measurement and Analysis written by R. Craig McClung and published by ASTM International. This book was released on 1999 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Load Interaction Effects on Fatigue Crack Growth in Ti 6Al 4V Alloy written by Robert Peh-ying Wei and published by . This book was released on 1973 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of delay, retardation in the rate of fatigue crack growth, produced by load interactions in variable amplitude loading, on the accurate prediction of fatigue lives of engineering structures is discussed. The effects of a broad range of loading variables on delay in fatigue crack growth at room temperature are examined for a mill annealed Ti-6Al-4V alloy. The results are used to estimate crack growth behavior under programmed loads.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prediction of Crack Growth Under Variable Amplitude and Spectrum Loading in a Titanium Alloy written by EP. Phillips and published by . This book was released on 2004 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present paper is concerned with the application of a plasticity-induced crack-closure model, FASTRAN, to predict fatigue-crack growth under various load histories in a thin-sheet Ti-62222 STA titanium alloy. This alloy was a leading candidate for a metallic High-Speed-Civil-Transport (HSCT) aircraft in the United States. The crack-growth model was based on the Dugdale strip-yield model but modified to leave plastically deformed material in the wake of the advancing crack. The model includes the influence of "constraint" on the development of plasticity and closure during constant- and variable-amplitude load histories. The model was used to correlate crack-growth-rate data under constant-amplitude loading over a wide range in crack-growth rates and stress ratios at two service temperatures (room temperature and 175°C). Tests on repeated spike overloads were used to help establish the constraint variations in the model. The model was then used to predict crack growth under two simulated aircraft spectrum load histories at the two temperatures. The spectra were a commercial HSCT wing spectrum and the Mini-TWIST (transport wing spectrum). This paper will demonstrate how constraint plays a leading role in the retardation and acceleration effects that occur under variable- amplitude and spectrum loading. The model was able to calculate the effects of repeated spike overloads on crack growth at the two temperatures, generally within about ± 30 %. Also, the predicted crack-growth behavior under the HSCT spectrum agreed well with test data (within 30 %). However, the model under-predicted the fatigue-crack-growth behavior under the Mini-TWIST spectrum by about a factor-of-two. Some of the differences may be due to fretting-product-debris-induced closure or three-dimensional effects, such as free-surface closure, not included in the model. Further study is needed on life predictions under the Mini-TWIST flight spectrum.

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 Aluminium Alloys written by Tibor Kvackaj and published by BoD – Books on Demand. This book was released on 2011-02-04 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book enhances in detail the scope and objective of various developmental activities of the aluminium alloys. A lot of research on aluminium alloys has been performed. Currently, the research efforts are connected to the relatively new methods and processes. We hope that people new to the aluminium alloys investigation will find this book to be of assistance for the industry and university fields enabling them to keep up-to-date with the latest developments in aluminium alloys research.

Download or read book Mechanics of Fatigue Crack Closure written by Wolf Elber and published by ASTM International. This book was released on 1988 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Some Aspects of Fatigue Crack Closure in Titanium Alloys written by C. J. Beevers and published by . This book was released on 1979 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth at intermediate rates and R 0.1 has been measured in compact tension specimens of the alloys Ti-6Al-4V and Ti-6Al-5Zr-0.5Mo-0.25Si. Crack length was determined from the output of a crack mouth displacement gauge and by using a d.c. potential drop technique. The incidence of crack closure was examined during fatigue by using both of the above methods; COD was found to be more reliable for closure measurement than potential drop. In contrast to the fine microstructured Ti-6Al-4V, the coarse Ti-6Al-5Zr-0.5Mo-0.25Si showed substantial load transfer across the crack faces during fatigue and this was attributed to a 'non-closure' mechanism. Low crack growth rates in the latter alloy were rationalized in terms of an effective delta K. Marked reductions in growth rate produced by variable amplitude loading ot Ti-6Al-4V could not be explained by crack closure. (Author).

Download or read book Fatigue Analyses Under Constant and Variable Amplitude Loading Using Small Crack Theory written by J. C. Newman (Jr) and published by . This book was released on 1999 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture and Strength of Solids VII written by Ahmad Kamal Ariffin and published by Trans Tech Publications Ltd. This book was released on 2011-01-20 with total page 1484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). This two-volume set of 339 peer-reviewed papers covers the broad areas of Composite, Polymer and Ceramic Materials, Fracture Mechanics and Mechanisms, Materials, Mechanical Structure, Strength and Dynamics, Interface Failure and Failure Analysis, Nano-Mechanics and Structures, Damage and Failure, Structural Design and Optimisation, Fatigue and Crack Propagation, Materials Modelling and Computation, Concrete, Rock and Soil, Dynamic Fracture and Impact, Erosion and Corrosion, Smart Materials and Structures, Biomechanics and Other Novel Methods of Computer Modelling in Engineering and Science.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Slip Character and Crack Closure on the Growth of Small Fatigue Cracks in Titanium aluminium Alloys written by James M. Larsen and published by . This book was released on 1990 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was performed to study the effects of slip character and crack closure on the propagation of small fatigue cracks in titanium- aluminum alloys. The materials examined were solution-treated Ti-4Al and Ti-8Al, as well as aged Ti-8Al. The propagation of naturally initiated surface cracks of depths as small as 25 micrometers was compared with the behavior of large through-thickness cracks. An extensometer was used to monitor crack closure throughout the large crack tests, and the closure behavior of the small cracks was measured using a computerized laser interferometric displacement gage having a displacement resolution of 0.01 micrometer. The measurements of crack closure were used to compute an effective stress intensity factor range. In all three alloys and for all test conditions, which included a range of stress levels and stress ratios, small cracks propagated faster than large cracks subjected to an equivalent Delta K, and the small cracks propagated under conditions that were significantly below the large-crack threshold, Delta K(th). Although the character and distribution of slip in Ti-Al alloys may have a dramatic influence on fatigue crack initiation and on the propagation of large cracks, this effect was minimal for small cracks.

Download or read book Mixed mode Fatigue crack Growth in Ti 6A1 4V written by Josh Patrick Campbell and published by . This book was released on 1999 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Constant Amplitude and Post overload Fatigue Crack Growth Behavior in PM Aluminum Alloy AA 8009 written by and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt: