The Conjoint Action of High and Low Cycle Fatigue.
Final rept. Jan-Dec 82,
PORTSMOUTH POLYTECHNIC (ENGLAND) MECHANICAL BEHAVIOUR OF MATERIALS LAB
Pagination or Media Count:
Fatigue crack propagation rates in Ti-6Al-4V subjected to relatively high frequency low amplitude vibrations superimposed on higher amplitude low frequency major cycles are studied. It is concluded that the vibrations, or minor cycles, have negligible effect below their fatigue threshold value. Above this level the minor cycles will contribute to the total growth rate their contribution, successfully predicted by the method of linear summation, is dependent on their relative number and size. In gas turbine and compressor discs and blades, components which experience large numbers of minor cycles per flight, the damage associated with active minor cycle is dominant. Consequently, the onset of minor cycle damage effectively determines the useful life of such components. Author
- Metallurgy and Metallography