Numerical Parametric Stress Analysis of the TF-30 Turbine Engine Third-Stage Fan-Blade/Disk Dovetail Region.
NAVAL RESEARCH LAB WASHINGTON D C
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A two-dimensional finite element parametric analysis was conducted for the diskblade dovetail region of the TF-30 turbine engine, assuming purely radial centrifugal loading of the blade. A graphical boundary matching procedure was used to determine a likely diskblade interface force distribution. This distribution produced a stress concentration factor SCF of 5.3 in the disk fillet, relative to the average stress in the neck section of the disk. In addition, the SCF was found to decrease with decreasing interface friction. Parametric modification of the disk fillet resulted in a maximum SCF reduction of 27, achieved with a fillet radius of three times the present one. For all studied combinations of interface force distribution, coefficient of friction and fillet geometry the point of maximum tensile stress occurred farther into the fillet away from the contact region than the point at which cracks appear to initiate near, or just into the inboard edge of the contact area. However, different combinations of interface force and fillet geometry result in different degrees of spread of the tensile stress concentration from the fillet area into the contact area. Finally, the effects of some assumed interface force perturbations due to non-radial non-centtrifugal loading are discussed. Author
- Attack and Fighter Aircraft
- Numerical Mathematics
- Jet and Gas Turbine Engines