A Modified Transfer Matrix Method for Modal Analysis of Stepped Rotor Assembly Applied in the Turbomolecular Pump

Table 5

The first two frequencies obtained by the modified TMM, modal test, and FEM.

	Modified TMM (Hz)	Modal test (Hz)	Error (%)	FEM with bonded contacts	Modified FEM in [6]
1st order frequency	3678.86	3784	−2.78	4545.2	3689.3
2nd order frequency	7461.67	7599	−1.81	9818.5	7577.1