@INPROCEEDINGS{Panning2004,
  author = {Lars Panning AND Karl Popp AND Walter Sextro AND Florian G{\"o}tting
	AND Andreas Kayser AND Ivo Wolter},
  title = {Asymmetrical Underplatform Dampers in Gas Turbine Bladings: Theory
	and Application},
  booktitle = {Proceedings of ASME TURBO Expo, Power for Land, Sea, and Air},
  year = {2004},
  volume = {6},
  number = {GT2004-53316},
  pages = {269-280},
  address = {Vienna, Austria},
  month = {June},
  abstract = {During operation, the rotating blades of a gas turbine are subjected
	to centrifugal forces as well as fluctuating gas forces, resulting
	in blade vibrations. In addition to material damping, aerodynamical
	and blade root damping, underplatform dampers are widely used to
	increase the amount of damping and to decrease blade vibration amplitudes.
	The friction forces generated by the relative displacements between
	the underplatform damper and the blade platforms provide a significant
	amount of energy dissipation. In practice, a number of different
	underplatform damper designs are applied. Basically, these are wedge
	dampers with flat contact areas, cylindrical dampers with curved
	surfaces or asymmetrical dampers with both flat contact surfaces
	on one side and curved contact surfaces on the other. The latter
	damper type combines the advantages of both the wedge and the cylindrical
	damper by preventing the damper from pure rolling on the one hand
	as it has been observed for cylindrical dampers and on the other
	hand, avoiding a diverged plane area contact in case of a wedge damper,
	causing a damper lift-off. This paper will focus on the investigation
	of cylindrical and asymmetrical underplatform dampers. A comparison
	between measurements of rotating assemblies in Siemens PG gas turbines
	(V84.2, V64.3A and V94.3A(2)) under test and real operating conditions
	with cylindrical and asymmetrical underplatform dampers and the predictions
	of the developed theoretical model are presented. Special attention
	is paid to the frequency shift due to the application of an underplatform
	damper, since in particular for stationary gas turbines, in addition
	to the amplitude reduction, the accurate prediction of the resonance
	frequency is of major interest.
	
	Copyright {\copyright} 2004 by ASME},
  bdsk-url-1 = {http://dx.doi.org/10.1115/GT2004-53316},
  doi = {doi:10.1115/GT2004-53316},
  keywords = {Dampers, Gas turbines},
  owner = {K. Agbons jr},
  timestamp = {2013.11.23}
}