Finding the resonant frequencies of a rotating shaft

A model of a rotating shaft was modelled on Solidworks, of total length of 30cm, a shaft diameter of 2cm, with a bearing diameter of 10cm. Alloy steel was assigned as its material and bearing fixtures were applied to the cylindrical faces of the stepped face. Then a frequency analysis was carried out obtain 5 mode shape diagrams and calculate the resonant frequencies of the rotating shaft. A direct sparse solver was used instead of FFEPlus as centrifugal load of 100 rad/s was applied to the shaft.

The initial setup:

The 5 Modal Frequencies obtained are:

Mode 1

Mode 2

Mode 3

Mode 4

Mode 5

The list of the resonant frequencies are:

Mode No.	Frequency(Rad/sec)	Frequency(Hertz)	Period(Seconds)
1	99.829	15.888	0.06294
2	1906.3	303.39	0.003296
3	1906.4	303.42	0.0032958
4	9173.1	1459.9	0.00068496
5	9173.4	1460	0.00068494