Griffin, "A review of friction damping
of turbine blade vibration," International Journal of Turbo and Jet Engines, vol.
However, there are rare reports about friction damping
coefficient between steel and rock obtained through experiment research.
where [C.sub.f] and [K.sub.f] are the friction damping
matrix and friction stiffness matrix respectively due to the contact mechanism and friction effects between the rotor and pad.
technology has already gathered 30 years of design experience (Szwedowicz, 2010) and can effectively reduce the resonance amplitude of interest by using under-platform dampers or by optimizing the shroud coupling.
where [T.sub.d] is the friction damping
torque, [J.sub.d] is inertial and [[omega].sub.d] is the angular speed of the damping flywheel.
is replaced by equivalent viscous damping in model.
This may not be a good predictor of an actual floor system with friction damping
. A second explanation may be related to boundary conditions.
Ferri, "Friction damping
and isolation systems," Journal of Mechanical Design, Transactions of the ASME, vol.
Griffin's findings have opened up friction damping
technology, which is now commonly utilized by many OEMs in gas and steam turbines.
The position of the peak amplitude shifts left first, with increasing [N.sub.t], because of the introduction of dry friction damping
. When [N.sub.t] is large enough, the influence of damping of the auxiliary support is offset by its stiffness effect, and the position of the peak amplitude starts to shift right.