Abstract
This paper studies on the transient vibration of bearing under runup and rundown of flexible rotor. The rotor / journal bearing system is modeled by FEM and integrated by Wilson's θ method in order to obtain transient amplitude and phase angle. Followings are concluded; the effect of transient response on the balancing is not so big for low increasing rotating speed and high damping, the fixed phase angle for fixed rotating speed which is not move by increasing and decreasing rotating speeds exists and it is very useful for the balancing of a flexible rotor, transient balancing is possible if data of both influence coefficients and unbalance response obtained by transient rotating speed is same. Error analysis of balancing weight and vibration after balancing was done for the case of different increasing speed of influence coefficient and unbalance response.
