Effects of Overloads and Creep on the Yield Surface of a Nickel-based Superalloy
- 67 Downloads
During typical flight cycles, a gas turbine blade is subjected to a complex multiaxial stress cycle due to the combination of centrifugal, thermal and gas loading stresses. Cyclic deformation of the blade occurs due to time-independent plastic strain and time-dependent creep strain. In the life prediction analysis of the blade account should be taken of the effects of deformation on the redistribution of the cyclic stresses. Before such calculations are possible, the multiaxial deformation behaviour of the material must be known, both during the first loading cycle and during subsequent cycles when the effects of work-hardening and prior creep are significant. For example, plasticity strains are estimated by assuming a multiaxial yield surface but the surface can be enlarged and distorted by previous loading cycles.
KeywordsAcoustic Emission Yield Surface Test Piece Bauschinger Effect Kinematic Hardening Model
Unable to display preview. Download preview PDF.
- Dudderar, T. D. and Duffy, J. (1967) Neutron irradiation and the yield surfaces of copper. Trans. Am. Soc. Mech. Engrs, E34, 200–9.Google Scholar
- Hodge, P. G. (1957) Discussion on Paper by W. Prager, J. appl. Mech., 79, 482.Google Scholar
- Michno, M. J. and Findley, W. N. (1974) Subsequent yield surfaces for annealed mild steel under servo-controlled strain and load histories. Trans. Am. Soc. Mech. Engrs, H.97, 25–32.Google Scholar
- Shiratori, E., Ikegami, K. and Yoshida, F. (1976) The subsequent yield surfaces after proportional preloading of the Tresca-type material. Bull J.S.M.E., 19, 1122–8.Google Scholar
- Winstone, M. R. (1983) Influence of pre-stress on the yield surface of the cast nickel super alloy Mar-M002 at elevated temperatures. Mechanical Behaviour of Materials—IV, J. Carlsson and N. G. Ohlson (Eds), Pergamon Press, Oxford, pp. 199–205.Google Scholar