The importance of the inclusion of disk flexibility on the natural fre
quencies' in a rotor dynamic analysis has attracted the attention of m
any researchers in the recent past.: Such an analysis helps to predict
the dynamic response of rotors more accurately from the natural frequ
encies and mode shapes calculated hence. In the present analysis a sem
i-analytical conical shell finite element is used for the modelling of
the rotor with the inclusion of the support bearing flexibility. Such
an element could include the flexibility of the disks, shaft and the
bearings. A parametric study was also performed for looking into the f
requency characteristics of the system. The study brings out the addit
ional disk modes a well as the behaviour of the system at higher circu
mferential modes. Copyright (C) 1996 Elsevier Science Ltd.