โ Scribed by S.A. Meguid; M.H. Refaat; P. Papanikos
No coin nor oath required. For personal study only.
Comprehensive finite element analysis and photoelastic studies using the stress freezing technique are made of the behaviour of aeroengine compressor discs under centrifugal loading. Specifically, the work is concerned with examining the effect of some of the critical geometric features and interface conditions in the dovetail region upon the least damage fail-safe design condition. These features included: inner and outer radii, flank length and flank angle, and coefficient of friction at the blade--disc interface. Two aspects of the work were accordingly examined. The first was concerned with the stressing of a number of discs containing the pertinent geometric features. The second was concerned with the initiation and subsequent propagation of cracks in regions exhibiting maximum stress concentration; the propagating cracks were then tracked using the maximum-minimum principal stress criterion. Finally, the theoretical predictions were compared with photoelastic spin tests. In this case, cracks which were introduced in the photoelastic models by careful sawing were extended incrementally along the theoretically predicted fracture path and isochromatic fringe patterns were recorded for each crack length. These fringe patterns were then used to analyse the stress field in the neighbourhood of the crack-tip.
๐ SIMILAR VOLUMES