The effect of random grain distributions on fatigue crack initiation in a notched coarse grained superalloy specimen
2012 (English)In: Computational materials science, ISSN 0927-0256, Vol. 51, no 1, 273-280 p.Article in journal (Refereed) Published
Coarse grained superalloys are of large interest in high temperature applications, and can be found in e.g.gas turbine components, where great care must be given with respect to high temperature fatigue. Due tothe large grain size, the material behaviour at e.g. sharp notches cannot be considered homogeneous. As aconsequence, the fatigue behaviour is likely to expose a large variation. In order to numerically investigatethis variation, a Monte Carlo analysis has been carried out by 100 FE-simulations of notched specimens,where placements and orientations of the grains were randomised. Furthermore, each grain wasmodelled as a unique single-crystal, displaying both anisotropic elastic and plastic behaviour and tension/compression asymmetry. The effect of randomness was investigated by the obtained dispersion infatigue crack initiation life. It was concluded that the fatigue life behaviour of coarse grained nickel-basesuperalloys may show a considerable variation, which cannot be captured by one single deterministicanalysis based on data for a homogenised material. Furthermore, the dispersion is of such a magnitudethat it needs to be taken into account in industrial applications where highly stressed coarse grainedmaterials are used.
Place, publisher, year, edition, pages
Elsevier , 2012. Vol. 51, no 1, 273-280 p.
Coarse grained superalloy, Fatigue crack initiation, Critical plane approach, Crystal plasticity, Monte Carlo analysis
National CategoryApplied Mechanics
IdentifiersURN: urn:nbn:se:liu:diva-72092DOI: 10.1016/j.commatsci.2011.07.054ISI: 000296214300034OAI: oai:DiVA.org:liu-72092DiVA: diva2:457022
Funding agencies|Swedish Research Council|
|Siemens Industrial Turbomachinery AB in Sweden||Swedish Energy Agency via the Research Consortium of Materials Technology for Thermal Energy Processes|
|National Supercomputer Centre in Linkoping, Sweden||2011-11-162011-11-162011-12-05Bibliographically approved