Short fatigue crack growth at elevated temperature
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Short fatigue crack growth at elevated temperature

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Published by Universityof Birmingham in Birmingham .
Written in English

Book details:

Edition Notes

Thesis (Ph.D.)-University of Birmingham, School of Metallurgy and Materials, 1990.

Statementby Joseph Cornelius Healy.
ID Numbers
Open LibraryOL13928069M

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Short fatigue crack growth tests have been carried out at room and elevated temperatures using the nickel-based superalloy known as Waspaloy. A fully automated computer controlled system has been The fatigue crack growth (FCG) and the FCG threshold behaviour of long cracks in L(N) material have been determined at °C. For the FCG behaviour an influence of R-ratio on the slope of the Paris law trend line was found with higher FCG rates in the range of low ΔK values for example R = The FCG threshold values decrease with increasing R :// Elevated temperature short crack fatigue test results At elevated temperature considerable surface oxide build up was noted, this unfortunately obscured much of the microstructure in the later portion of the fatigue Short cracks and durability analysis of the Fokker wing/fuselage structure; high cycle fatigue crack initiation in stainless steels; fatigue crack initiation and early crack growth in copper polycrystals - effects of temperature and environment; the growth behaviour of microstructurally small fatigue cracks in metals; some aspects of small crack growth near threshold in dual phase steel

The effect of hold-time on fatigue crack growth behaviors of WASPALOY alloy was investigated. It was found that the role of hold-time depends on the competition between the harmful environmental effect and the beneficial effect of creep. If temperature is not higher than °C, fatigue crack growth rate of WASPALOY alloy increases with :// Zr-based bulk metallic glasses (BMGs) are surprisingly susceptible to cyclic fatigue processes. In the present study, the sub-T g elevated temperature fatigue crack growth behavior was fatigue threshold, ΔK TH, was found to increase from ∼ to ∼ MPa m 1/2 as testing temperature was increased from to °C. Low levels of fatigue crack closure were apparent and not At elevated temperatures, time dependent deformation or creep sets in (see High Temperature Fatigue and Thermomechanical Fatigue). At elevated temperature, the initial response of the stress field ahead of a crack-tip can be described by K I or J I ; but since these parameters are independent of time, they cannot characterize the crack-tip In general, the temperature varies between a high operating temperature and a low non-operational ambient temperature. As a result of the temperature profile, cyclic thermal stresses can be introduced. High-temperature fatigue conditions imply that the fatigue load and temperature

  @article{osti_, title = {Materials and design bases issues in ASME Code Case N}, author = {Huddleston, R L and Swindeman, R W}, abstractNote = {A preliminary evaluation of the design bases (principally ASME Code Case N) was conducted for design and operation of reactors at elevated temperatures where the time-dependent effects of creep, creep-fatigue, and creep ratcheting A study was done to determine the fatigue crack growth behavior of a PWA single-crystal nickel-base superalloy in a temperature range of °C to °C. Two distinctive failure modes were observed, which were a function of both temperature and ://   Short fatigue crack growth in a nickel base superalloy at room and elevated temperature. Int J. Fatigue, , 38 S. S. Tschegg. Fatigue crack growth and thresholds at ultrasonic frequencies. Int J. Fatigue, , 39 T. L. MacKay. Fatigue crack propagation rate at low K of two aluminium sheet alloys, T3 and ://   fatigue crack propagation behavior of a wrought nickel-base superalloy, R with reference to the effect of crack size on the threshold stress intensity AK o for no detect- able crack growth. Measured threshold AKo values at low load ratios (R = ) for physi- caUy short ( - mm) cracks were