Download or read book Influence of High Frequency Vibrations on the Low Cycle Fatigue Behavior of a Superalloy at Elevated Temperature written by Ouyang J and published by . This book was released on 1988 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of relatively high-frequency, low-amplitude vibrations on the low-cycle fatigue (LCF) behavior and its fractographic feature for a GH36 Fe-Ni alloy at 600°C is studied. It is found that the influence is rather complicated and significant. The nature and extent of the influence depended upon the ratio of the amplitude of high-cycle to low-cycle stress range, Q. As Q approaches Qc (the critical value of Q), there is no appreciable influence on the total LCF life; as Q Qc, it will prolong the lifetime slightly; and as Q Qc, the fatigue life will decrease progressively. The variation of fatigue life was ascribed to the occurrence of some considerable interactions between creep, high-cycle fatigue (HCF), LCF, and environmental effect under different values of Q at elevated temperature, and the change of damage mechanism of the material. The total LCF life, especially crack propagation life, will be markedly reduced by the high-cycle vibrations when Q is much greater than Qc. Meanwhile, the mixed failure of creep, HCF, LCF, and environmental attack will gradually change into combined cycle fatigue failure with increasing Q. The fractographic analysis is in agreement with these results.

Download or read book Low Cycle Fatigue written by Harvey D. Solomon and published by ASTM International. This book was released on 1988 with total page 1289 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Cycle Fatigue written by Theodore Nicholas and published by Elsevier. This book was released on 2006-07-07 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr Theodore Nicholas ran the High Cycle Fatigue Program for the US Air Force between 1995 and 2003 at Wright-Patterson Air Force Base, and is one of the world's leading authorities on the subject, having authored over 250 papers in leading archival journals and books. Bringing his plethora of expertise to this book, Dr Nicholas discusses the subject of high cycle fatigue (HCF) from an engineering viewpoint in response to a series of HCF failures in the USAF and the concurrent realization that HCF failures in general were taking place universally in both civilian and military engines. Topic covered include: - Constant life diagrams - Fatigue limits under combined LCF and HCF - Notch fatigue under HCF conditions - Foreign object damage (FOD) - Brings years of the Author's US Air Force experience in high cycle fatigue together in one text - Discusses HCF in the context of recent international military and civilian engine failures

Download or read book Effects of Temperature and Frequency on the HCF Behavior of a Ni based Superalloy written by and published by . This book was released on 2005 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book hold time effects in high temperature low cycle fatigue written by and published by ASTM International. This book was released on 1971 with total page 37 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:

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 High Temperature Low Cycle Fatigue Mechanisms for a Nickel base and a Copper base Alloy written by Chin-I. Shih and published by . This book was released on 1982 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1988 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High temperature Low cycle Fatigue Experiments on Hastelloy X written by A. E. CARDEN and published by . This book was released on 1969 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the ASME Turbo Expo written by and published by . This book was released on 2004 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Superimposed Stresses at High Frequency on Low Cycle Fatigue written by Guedou J-Y and published by . This book was released on 1988 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of superimposed stresses at high frequency on low cycle fatigue behavior were studied on two aeronautical alloys (Ti 6-4 and Inconel 718) in terms of crack initiation, crack propagation, and failure. It is shown that, if the minor cycles have limited amplitudes, not more than 10 to 15% of low cycle fatigue stresses, the life is monitored by the maximum stress of the cycles. This is correlated with the fact that, in this case, the endurance limit of the material is not exceeded. The same criterion is suitable for crack initiation of Inconel 718, but not for Ti 6-4 which is, in all cases, much more sensitive to mixed fatigue than Inconel 718.

Download or read book The Fatigue Behavior of NiCr22Co12Mo9 Under Low Frequency Thermal Mechanical Loading and Superimposed Higher Frequency Mechanical Loading written by M. Moalla and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The repeated start-ups and shut-downs experienced by gas turbines cause complex thermal-mechanical loading, which may result in the low-cycle fatigue failure of components such as the walls of the combustion chambers. In addition, a higher frequency high cycle fatigue loading (HCF) is often superimposed due to mechanical vibrations and unsteady combustion processes. It is known that such a superimposed HCF loading may not only change the cyclic deformation behavior, but also reduce the lifetime considerably. In the present study, the cyclic response of a combustion chamber material, NiCr22Co12Mo9 (Inconel 617), was investigated under combined TMF/HCF loading in total strain controlled out-of-phase (OP) and in-phase (IP) TMF tests with and without superimposed HCF loading. The minimum temperature of the TMF tests was 200 °C, and the maximum temperature was varied from 750 to 1200 °C. For each maximum temperature condition, the superimposed HCF amplitude was varied between 0 and 0.2%. Cyclic hardening was observed, but it became less pronounced the higher the maximum temperature, and at the highest Tmax the material was cyclically neutral. With increasing superimposed HCF amplitude the cyclic deformation behavior was more and more determined by the HCF. Further, as a result of the superimposed HCF loading the TMF lifetimes decreased significantly. In general, the lifetimes decreased with increase in HCF amplitude and approached only 10% of the fatigue lifetime obtained in the pure TMF experiments. The relation between the applied total strain amplitude, ?a,tme,and the number of cycles to failure, Nf, could be expressed as ?a,tme = A • Nf-b for each Tmax and type of TMF-test. With the use of this empirically determined relationship it was possible to estimate the lifetime reduction caused by a superposition of a higher frequency HCF loading on the OP- as well as IP-TMF loading.

Download or read book An Investigation of High Temperature Low Cycle Fatigue Behavior of Materials written by Christopher L. Hoffmann and published by . This book was released on 1981 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Stress State on High temperature Low cycle Fatigue written by Christopher Robin Kennedy and published by . This book was released on 1963 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Engine Structures written by and published by . This book was released on 1988 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elevated Temperature Fatigue Behavior of Tungsten Fiber Reinforced Superalloy Composites written by JL. Yuen and published by . This book was released on 1994 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low-and high-cycle fatigue behavior of three different fiber-reinforced superalloy (FRS) composite materials were evaluated. Each composite material contained 40 vol% unidirectionally aligned continuous length tungsten-1.5 wt% ThO2 fibers. The metal matrices were Waspaloy, Type 316L stainless steel, and Incology 907. Fatigue tests were conducted at 871°C in a helium atmosphere under load control with a load ratio (minimum stress/maximum stress) of 0.2. The composites were found to have excellent elevated temperature fatigue strength. The fibers played a major role in controlling the fatigue strength of the composites. Fatigue crack fronts were found to be retarded by the fibers. The cracks tended to branch at the fiber/matrix interface and grew by a sliding mode along the interface. Matrix surface cracks induced by thermal shock damage had little influence on the fatigue strength of the FRS composites.