Download or read book Load and Environment Interactions in Fatigue Crack Growth Under Spectrum Loading written by R. P. Wei and published by . This book was released on 1978 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of delay (or, retardation in the rate of fatigue crack growth) produced by load interactions in variable-amplitude loading on the accurate prediction of fatigue lives of aircraft and other engineering structures has been recognized for some time and has begun to receive greater attention in recent years. Recent investigations showed that the effects of delay can be quite large, and that these effects need to be taken into account in developing improved fatigue analysis procedures for aircraft and other engineering structures. A number of models (based on the concepts of crack closure, residual stress intensity factor, etc.) have been proposed to account for the effects of delay. These models, while successfully predicting trends in the rate of fatigue crack growth for randomized load spectra, appear to break down for ordered spectra. Several basic problems contributed to the lack of complete success, and needs to be resolved in the development of improved models for predicting load interaction effects (chiefly delay) on fatigue crack growth.

Download or read book Load and Environment Interactions in Fatigue Crack Growth written by T. T. Shih and published by . This book was released on 1974 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influences of environment on delay and on fatigue crack growth under programmed loading were examined for a mill annealed Ti-6Al-4V alloy. Test environments included dehumidified argon, air (with 30-60% relative humidity), distilled water, and 3.5% NaCl solution. The effects of load sequence and block size on fatigue under programmed loads were investigated also. Experimental results show that the mildly aggressive environments (atmospheric moisture and distilled water) have little effect on delay. Salt solution, on the other hand, has a significant effect on delay and on crack growth under programmed loading; the effect on delay being dependent on frequency or hold-time. Both load sequence and block size can significantly alter fatigue life under programmed loading. The need for further fundamental understanding of load and environment interactions in fatigue is discussed. (Modified author abstract).

Download or read book Load Environment Interaction Effects on Crack Growth in Landing Gear Steels written by MS. Rosenfeld and published by . This book was released on 1982 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent research into the crack growth behavior of aircraft landing gear steels shows that combinations of aggressive chemical environment and high sustained loading can cause significant reduction in the fatigue crack growth life of 300M steel. Crack growth behaviors of 300M and HP 9-4-0.30 steels are compared for continuous salt water immersion and alternate immersion in synthetic sea water environments. An analysis approach which sums the crack growth due to cyclic loading in an inert environment is shown to accurately correlate and predict the combined effects of chemical environment and mechanical loading on crack growth. Crack growth behavior under landing gear stress spectra typical of Air Force and Navy usage is compared.

Download or read book Load Interaction Effects on Fatigue Crack Growth written by Stoyan Ivanov Stoychev and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Creep fatigue environment Interactions written by R. M. Pelloux and published by American Society of Civil Engineers. This book was released on 1980 with total page 216 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 and published by . This book was released on 1973 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth Behavior of Ti 1100 at Elevated Temperature written by DC. Maxwell and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of temperature, frequency, and cycles with superimposed hold times are evaluated in Ti-1100 in order to study the complex creep-fatigue-environment interactions in this material. Crack growth rate tests conducted at a cyclic loading frequency of 1.0 Hz show that raising the temperature from 593 to 650°C has only a slightly detrimental effect on crack growth rate, although these temperatures produce growth rates significantly higher than at room temperature. From constant ?K tests, the effects of temperature at constant frequency show a minimum crack growth rate at 250°C. From the minimum crack growth rate at 250°C, the crack growth rate increases linearly with temperature. Increases in frequency at constant temperatures of 593 and 650°C produce a continuous decrease in growth rate in going from 0.001 to 1.0 Hz, although the behavior is primarily cycle dependent in this region. Tests at 1.0 Hz with superimposed hold times from 1 to 1000 s are used to evaluate creep-fatigue-environment interactions. Hold times at maximum load are found to initially decrease and then increase the cyclic crack growth rate with increasing duration. This is attributed to crack-tip blunting during short hold times and environmental degradation at long hold times. Hold times at minimum load show no change in growth rates, indicating that there is no net environmental degradation to the bulk material beyond that experienced during the baseline 1 Hz cycling.

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 Influence of Load Interactions on Crack Growth as Related to State of Stress and Crack Closure written by and published by . This book was released on 1985 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Environment and Complex Load History on Fatigue Life written by American Society for Testing and Materials and published by ASTM International. This book was released on 1970 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth under Spectrum Loads written by and published by ASTM International. This book was released on 1976 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of the Environment on the Initiation of Crack Growth written by William Alan Van der Sluys and published by ASTM International. This book was released on 1997 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Role of Environment on Time Dependent Crack Growth written by and published by . This book was released on 1981 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gaseous as well as aqueous environments are known to accelerate time dependent crack growth under either static loading (SCC or HE) or dynamic loading conditions. In some cases, the rate controlling processes of these phenomena have been related to surface controlled reactions, while in other cases bulk reactions such as diffusion appear to be rate limiting. It is not entirely clear that the mechanisms of time dependent crack growth are identical for different environment/alloy couples, or for different ranges of loading conditions. This paper will attempt to examine the chemical aspects of environment/alloy interactions and to correlate those aspects with observed crack propagation rates under a variety of loading conditions at or near room temperature. Additionally, a brief discussion of the role of environment on elevated temperature fatigue crack growth will be presented. (Author).

Download or read book Cyclic Stress Strain and Plastic Deformation Aspects of Fatigue Crack Growth written by L. F. Impellizzeri and published by ASTM International. This book was released on 1977 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cyclic Stress Strain and plastic deformation Aspects of fatigue crack growth written by L. F. Impellizzeri and published by ASTM International. This book was released on 1977 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Load Interaction Effects in Fatigue Crack Propagation written by O. A. Adetifa and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Load interaction Effects in Fatigue Crack Propagation written by and published by . This book was released on 1990 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: A systematic investigation has been carried out on the mechanisms of the retardation in fatigue crack propagation following either a single overload or a large number of multiple overloads. The results from A1 alloy 6061-T6 and 9Cr-2Mo steel confirmed the observation by Paris and Hermann that during the period of retarded fatigue crack growth subsequent to the application of a single overload, two instead of only one crack opening levels exist.