Effect of Crowning of Dovetail Joints on Turbine Blade Root Damping
Stresses due to resonant vibrations induce fatigue damage in turbomachinery blades jeopardizing their structural integrity. Damping plays a fundamental role in passive control of resonant stresses. In the present work the effect of ‘crowning’ of dovetail joints on blade-root friction damping is for the first time investigated. In detail, the damping of a simplified blade is measured under varying centrifugal load for two different joint geometries: a customary dovetail attachment and a ‘crowned’ one. A theoretical model is developed to quantify the damping generated at the contact surfaces. Experimental results and analytical predictions are compared.
L. Garibaldi, C. Surace, K. Holford and W.M. Ostachowicz
M. Allara et al., "Effect of Crowning of Dovetail Joints on Turbine Blade Root Damping", Key Engineering Materials, Vol. 347, pp. 317-322, 2007