Effect of the Supports’ Positions on the Vibration Characteristics of a Flexible Rotor Shafting

Table 3

First four natural frequencies and modes of the flexible rotor shafting system.

N	(Hz)	Mode description
1	53.273	FW; first-order bending vibration
2	53.665	BW; first-order bending vibration
3	111.28	FW; second-order bending vibration
4	111.5	BW; second-order bending vibration

Frequencies are reported in ascending order 1 to 4;  = natural frequency of mode N; FW = forward whirl; BW = backward whirl.